Local accounts, yes. How are you bypassing Microsoft accounts with 2 factor authentication enabled? Unix and Mac passwords were the same for local accounts before.

Easiest way right now would be to acquire a username password to get into their phone provider, say Verizon. Then log into their Verizon account and move their phone number to a new phone. (this will only require knowledge of their security questions, also a phone not purchased by a card or registered to you if you don't want it traceable)

Once done then you can reset the password using the unknown password to their Microsoft account using the 2 factor that sends to their phone number....maybe.

Especially on windows 11 we don't stand much of a chance getting passed.

Likely easier to pick up the password book they wrote all of their passwords down in and accessing them. (Performed by most people over 50 I know)

Edit: also, you will find their Facebook password written there haha