I mean, these are fintech companies we're talking about here. If you're signing up for these services your generally already deciding to trust the company with personal data. Plus, you still have to login to your online banking with Plaid, it's not like developers have unlimited, unauthorized access to you r account balance and transaction information.

There's a difference between - "I am paying you with ACH routing and account information" and "The payment platform exposes, to the app, my account balances". A huge difference.