> Not really, considering it doesn't enforce a single, consistent API, so most companies will still use something like TrueLayer (our local equivalent of Plaid) to aggregate all these separate APIs into a single consistent one.

That's not quite true. The CMA9 have to follow the Open Banking spec, and some other non-cma9 banks have decided to follow the same spec. In practise, there's some deviation from the spec between the banks (in part, due to ambiguity in the spec), but it's not like they're all pulling their own spec out of the air.

> 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.

The 'deep pockets' don't need to be as deep as implied. I think it's <~£3k. It's not something that only big companies can afford, but I agree, it's not something that an individual would use to test out an idea, which would push them towards something like TrueLayer.