Yeah there will be that but if I'm not mistaken it isn't the banks who need to authorise individual API providers. There is a directory of allowed services that

Yeah there will be that but if I'm not mistaken it isn't the banks who need to authorise individual API providers. There is a directory of allowed services that get whitelisted by the Open Banking "consortium" - I don't think a bank can then deny any requests coming from that list. However, you're still correct because to get whitelisted by Open Banking is in itself a long process and has requirements that makes it unfeasible for many small service providers.