The new Global Perspectives & Solutions (GPS) report from Citigroup (C) says that U.S. bank staffing will dive 30% between 2015 and 2025, from 2.6 million to 1.8 million. (It’s already down from a pre-crisis peak of 2.9 million.) And things are even tougher in Europe, where bank branch employment is expected to drop from 2.9 million to 1.8 million.

According to Citi, as more transactions are automated and done on mobile phones, bank staff will be shifted from performing transactions to advisory roles. But the question is whether banks will able to do that fast enough, and whether that move will save them.

New firms like OnDeck (ONDK), Coinbase, Lending Club (LC), and Square (SQ) have begun to gnaw away at many of the activities that might have brought consumers and small business owners into bank branches. American and European banks are now—like taxi drivers a few years ago—facing what the report calls their “Uber moment.”

“In the U.S. and Europe, only a very small fraction of the current consumer banking wallet has been disrupted by FinTech so far. However, this is likely to rise,” the report says. “An open question remains as to whether incumbent banks in the U.S. and Europe can embrace innovation, not just talk about Blockchain and hack-a-thons, before FinTech competitors gain scale and distribution.”

FinTech companies are going after banks’ most profitable services. Citi says that personal and small and medium enterprise (SME) banking accounts for about half of the banking industry’s profits, and over 70% of the FinTech investments have gone into those segments.

Other countries have passed their “Uber moment” tipping point. According to Citi, China is the world’s peer-to-peer lending leader, at $66.9 billion. FinTech companies there also have as many customers as do traditional banks, the report says.

Not everybody is confident that U.S. and European banks can evolve. “In my view only a few [incumbent banks] will have the courage and decisiveness to win in this new field,” Antony Jenkins, the former CEO of Barclays, said in a recent speech in London. “I predict that the number of branches and people employed in the financial services sector may decline by as much as 50% over the next 10 years, and even in a less harsh scenario I expect a decline of at least 20%.”