I would expect competition at some point. Hell, it is likely to come from the existing banks. If the USG starts to give them access, the customer bases of the existing entities will give them a big leg up.
To me, there will come a time when someone can send their crypto to their bank and swap it for fiat, at least stablecoins. If the banking system can hold USDC or USDT, then it is likely possible to do that. That could cut out a lot of Coinbases transactions.