If just one or those passwords gets leaked you might find a lot of other ones get cracked as well.
It may not be sites that you care about. But using a password manager is a lot less effort and a lot safer than whatever technique the average Joe will come up with.
Any password that leaks which could indicate a potential system ( e.g.: sitename in lower/upper/leetspeak) makes the whole thing even more vulnerable.
Just use something. Bitwarden, vault warden, keepassxc, …
Knowing my social circle I’d recommend bitwarden. Even paying for it costs a measly 10$/year, while the free version is very usable in itself. And generating passphrases or 32char passwords will be a lot safer than whatever the hell they can come up with.
Just avoid the default browser ones, big tech and LastPass.
Why would you want it to automatically grab money from your savings? Wouldn’t you just want to transfer that yourself?
I feel like it’s an extra guardrail that if somebody tries to pull 3000$ from your bank account and you only have 500 there that it can only pull the 500 and not the additional 2500 from your savings account?