I absolutely love the idea.
Problem, I don’t trust 3rd party services with access to financial data. No offense to the OP.
I wish this was open source and self-hostable. Not suggesting that OP does that since I’m sure he has to pay bills :)
I may look into doing something like this for personal use. I’ve gotten interested in creating desktop apps which store data locally. Have created a few using Claude code. It seems Plaid has some APIs for personal use.