The move was notable not just because a top executive was quickly exiting a big deal, but also because of where he was going. TWC has a market cap of over $50 billion. WeWork doesn’t have a market cap or a ticker symbol. It’s not a public company. Based on WeWork’s latest round of financing, it is worth roughly $5 billion.

Minson’s departure was yet another data point in the battle for economic influence between startups and largest companies in America. Add up the anecdotes and it appears that big companies are losing badly. This week, George Zimmer, the former CEO of clothing giant Men’s Wearhouse, said that he too was launching a startup, which he claimed would be the “Uber for tailors,” referring to the ride-sharing app company that, according to its latest financing, is worth more than $50 billion.

These days, there are dozens of private companies, mostly new tech startups, that are worth more than $1 billion. These companies are nicknamed unicorns, but they’re not hard to find. There are lots of them. (Fortune has a list.) And, like magic, they are taking over the economy.

At the same time, the list of struggling large companies seems longer than ever. McDonalds’ CEO was forced out earlier this year, after a string of dismal quarterly performance reports. IBM’s shares have fallen 13% over the past three years. And Walmart’s sales and profits rose a meager 2% last year. The list of reasons for the disappointing performance are long too, from changes in technology, regulations, to consumer tastes. (Read Fortune’s recent special report, The war on big food.)

That’s gotten the attention of activist shareholders, who are increasingly targeting larger companies, which were long considered out of reach among the rabble rousing hedge funds. One of the most regular demands from the activists: Break-up. On top of that, a strong dollar and weak overseas economies have put a big dent in the bottom lines of a number of large companies.

This week Fortune published the latest version of the Fortune 500, our annual list of the largest companies in America. But, in the age of Uber, have the biggest companies in America lost their relevance? Not quite. Despite all of the issues they are facing, big companies in general are doing quite well. Large companies are getting a larger slice of overall U.S. corporate profits than ever before. Top recruiters, despite a few notable exceptions, say big companies are having no trouble hanging onto top talent. And venture capitalists, some of the biggest promoters of the startup economy, say that it’s still the big companies that set the standards. What’s more, the Fortune 500 is a constantly rejuvenating list, with new economic powerhouses joining the ranking every year. This year, the Fortune 500 had 26 new entrants, including Netflix.

And large companies employ more people than ever before. Collectively, the Fortune 500 employs nearly 27 million people. That’s up from 24 million a decade ago.

“Companies like IBM still matter,” says Daniel Friend, who leads investments in mid-sized companies at Bain Capital Ventures. “They may be doing less innovation, but they are still at the heart of defining how innovation occurs.”

The war for talent

Minson’s move from Time Warner to WeWork was notable. But it has also been the exception. In 1999,George Shaheen, the CEO of Anderson Consulting, which is now Accenture, made big news when he bolted for Internet grocery delivery startup Webvan. Unlike in the 1990s tech boom, though, there haven’t been a lot of departures of top executives form big companies to startups. Joe Griesedieck, who is vice chairman of recruiting firm Korn/Ferry’s board and CEO search division, says being the CEO of a big company is not nearly as much fun as it used to be. Nonetheless, Griesedieck says, “I don’t see a lot of people looking to jump ship.”

Part of that reluctance has to do with pay. Griesedieck says the big companies still pay quite well. According to an Equilar study, that was published by the New York Times, the average pay for a Fortune 200 CEO last year was $22.6 million, up from $20.7 million the year before and the highest it was been since Equilar began tracking these figures in 2006.

Also, recruiters say that they and executives have learned lessons from the 1990s. Big companies aren’t like small companies. Most small companies have their own unique culture. Many executives who tried to make the switch back in the late 1990s ended up not doing well. “Startups often want the credibility that comes with someone who has worked at a Fortune 500 company, but the cultural fit part is very important,” says Ron Lumbra, a managing director and co-leader of Russell Reynolds Associates’ CEO and Board Services Practice in the Americas.

But the influence game goes both ways. The fact that fewer large company executives are landing at startups means more startups are even freer of the influence of big business. People running startups today think less of big company executives. EVA’s Stewart says startups have figured out how to run things themselves. “There’s a Steve Jobs effect going on,” says Bennett Stewart, who is the founder of financial technology consulting firm EVA Dimensions, which focuses on the amount of economic value companies are creating. “Apple didn’t do well when it brought in a seasoned executive. Startups don’t think they need so-called ‘adult-supervision’ anymore.”

Profits

Last year, the Fortune 500 made a combined $945 billion in profit. That was 13% lower than 2013, which was a record. But it’s still far more money than the largest companies in the nation have ever made in the past. The last time profits at the Fortune 500 peaked was in 2006. Back then, the 500 companies made a combined $785 billion. Profits are 20% higher now.

Fortune 500 companies appear to account for a very large piece of the U.S. corporate profit pie. Two decades ago, the profits of Fortune 500 companies equaled 3.7% of GDP. Two years ago, that percentage reached 6.4%. Last year, it fell to 5.3%.

That number is a bit misleading, though. More of the profits of the companies in the Fortune 500 companies are coming from overseas. Those profits are not counted in GDP. Coca-Cola, for instance, has struggled in the U.S. as consumers have become more health conscious, but the company is still growing overseas.

Nonetheless, consolidation in many industries means that the U.S.’s larger companies are almost certainly earning a larger percentage of the economy’s profits than they used to. And even within the Fortune 500 a smaller group of companies are getting a great share of the profits. For example, the 20 most profitable companies in the Fortune 500 last year accounted for nearly 37% of the entire cohort’s total profits. That’s up from 30% two decades ago.

“Large companies are thriving,” says consultant Stewart. “Apple and Google, for instance, are doing quite well.”

Influence

Startups like Uber and AirBnb do seem to be changing the landscape of the economy. But both are in industries, taxis and hotels, that haven’t changed in years and were probably due for a shakeup. A better measure of big company versus startup influence might be the recent battle over net neutrality. Net neutrality clearly benefits startups versus the cable giants. And in the end, it appears the government has sided with smaller companies. But the fight over net neutrality was really fought by large firms, and won in large part by Netflix, which is now a Fortune 500 company.

And when it comes to new computer platforms or technology, it’s still often the bigger firms that are setting the agenda. Cloud computing, for instance, is being shaped by Amazon, IBM, and Microsoft. Google has more influence than anyone over how websites are built. And even Apple and others innovating in the mobile payments business have to live by the specifications set up by American Express, Visa, and others in the finance industry.

“There is always a fascination with the new-new thing,” says Yale leadership professor Jeffrey Sonnenfeld. “But the idea that big companies can’t compete and stay nimble hasn’t been proven out.”