The corporate players in the space can jump through the security hoops and integrate with Plaid, but if I wanted to automatically pull my own data into the single-user budgeting tool I host entirely on my own network I need to pass the same security checks as a full-on fintech startup.
Currently I enter transactions manually, but manually reviewing multiple credit card and bank statements is a chore and I don't keep up with it as much as I should. To make things worse, since I ideally want a live view of my budget and not a post-statement-issuance monthly review, I'm constantly checking over transactions I've already entered when their ordering changes in my credit card company's app.
The closest thing to a potential solution involves extracting my Monarch Money session key from my browser and pulling data from their GraphQL endpoints with the help of an unofficial Python SDK. That doesn't solve the "relying on a subscription service" problem, but it would at least let me get my data into the custom budgeting tool I built that actually meets my needs.