Thoughts and opinions are my own being adjacent in financial services.

Checks? Rapid decline with eventual phase out. Western Union will be forced to pivot to international remittance to maintain volume. Credit card companies will see a fate similar to checks but over a longer window of time (but will still maintain some volume) depending on consumer and merchant incentives (passing the credit card cost to consumers, for example, while not charging for Fed instant payments). Crypto? Stablecoins are looking like they'll be regulated by the gov and require a banking license to issue. See Matt Levine's latest Money Stuff "The Fed vs. stablecoins" segment on this [1] [2] [3].

[1] https://pastebin.com/VAPra5sY

[2] https://news.ycombinator.com/item?id=30167748

[3] https://www.federalreserve.gov/econres/ifdp/stablecoins-grow...

Here in India, the credit card business is booming despite UPI (i.e. better FedPay). The value proposition of credit card is unconditional short term credit. There is also the additional consumer protection through chargebacks. Popular credit card companies have moved to offering actual short term (<1 year) loans via the card. I don't think Credit cards would be going away anytime soon.

Consider Affirm and Afterpay in the US. This is what I believe the future of short term payment credit looks like when you have instant payment rails. You could even "overspend" your deposit account, with the negative balance being credit, dynamically managed by your deposit account provider's risk management system. The well off can do this with a margin account at their brokerage, but there's no reason this can't be done with your bank or fintech with personal credit. Several big commercial banks even underwrite your credit profile based on your deposit account cashflow vs your credit score (JPMC, for example).

EDIT: Check out https://cred.ai/ for an example of a financial product this might look like, from a quick Google search. No affiliation.

Credit cards aren't going away, but they're also no longer going to be the least worst solution for payments and transfers where assurances are needed. They're antiquated value transfer rails imho (and I'm aware the chief benefit of CCs are the 20-30 day float, longer with interest). In summary, the credit is the product, the rails are the utility, and there are many ways to issue and manage that credit.