To add an interesting layer, financial institutions are investing in these solutions. Goldman previously invested in Plaid, and Fidelity invested in Quovo which takes a similar approach.

At some point I think it's on the banks to offer OAuth APIs, then Plaid can swap out one-by-one (if it hasn't already started).

Nylas is facing the same challenge in the email space. They have oauth for gmail, but user/pass for Exchange/SMTP.