Earlier quoted context omitted.
Yeah, banks could have done oauth2 years ago but it never happened.
Open Banking in the UK does that now.
Furthermore, "open" banking is very misleading because it's only open to corporations with deep pockets to obtain an AISP license/certification*, but doesn't even allow the account holder to gain API access to their own account. Unless you're lucky enough to be with a modern bank that provides that as a feature (which is legally separate from Open Banking, though often it's the same API), your only workaround is to sign up for TrueLayer yourself just to access your own account through them.
* given the "deep pockets" requirement, it almost forces all the account aggregator apps/services (Emma, Yolt, etc) to have a somewhat scummy business model and monetize the captured data. Wouldn't it have been nicer that you didn't need deep pockets to gain read-only access, so that an indie developer could make such an account aggregator and not have to resort to a scummy business model to fund the certification/compliance expenses?