"One does not give out their password"

Actually, you do "give out" your password every time you log in to any website or service. You enter your credentials into the little box and you have no idea where they go. It's a risk that is impossible to avoid. And as you note, thieves don't even need to hack you to get your login info; it is probably already available online.

I won't vouch for Plaid in particular, but because most institutional systems don't talk to each other, intermediaries like Plaid are needed to provide integration and convenience. Mostly, their login systems are as secure as the banks'. So while I admire your spirit, avoiding Plaid is unlikely to make you any safer.

I'm a privacy nut, but also a realist. Until biometrics are ubiquitous, the best protection for most people is to use two-factor authentication (and passkeys) routinely, and change your passwords (stress on plural) on a regular basis.

abromber