Plaid isn't a solution to a technical problem. It's a way to deal with the fact that banks don't want their customers to bypass their websites/apps and the cross-selling ads within.
Re:Passkeys now support external providers
by TheNewsIsHere on Tuesday June 06, 2023 @09:56AM
(#36212845)
In their defense, Plaid also very quickly demonstrated why you might not want an online bank access free for all. At least in privacy-centric terms.
This is an anti-pattern, and is not worth supporting in new tech that's supposed to be "secure first".
We already have tech for delegating authorization.