I was originally excited for Open Banking but now it turns out to be for naught. Sorry to ruin your joy.
I was expending that at the very least the directive would mandate a standard protocol/API format that all banks would conform to - that does not seem to be the case. For each bank you’d like to interconnect with, you have to integrate with their unique API. As a company that is a huge burden to integrate & keep up to date with every single bank’s API.
My other disappointment is because of regulations and certification requirements to become an “AISP”. It might make sense for online services that access and store your banking data on your behalf, but is counter productive for local-only apps that do all processing on your device where there is no risk of data being compromised. It’s even worse when banks don’t even let me access my own account over the API, and if they do, it’s still not up to the full extent of what Open Banking was supposed to provide (I still can’t initiate bank transfers from the Monzo API for example).
Overall I feel like “open” banking will just help out a few established players that have the means to meet all the nonsensical certification requirements. With the lack of competition those companies will stagnate and become what we call “legacy”. Many successful software projects started as a side gig with a prototype on spare time without external funding - but sadly none of those would be possible with “open” banking due to the barrier of entry.