If they crack your password manager you're dead. No single points of failure 👀

If my login information is breached, I'm protected by my 2FA codes. If my 2FA codes are breached, my login information are still safe. 2FA is meant to provide extra security. This is pointless if your login info and 2FA info are in the same place.

No one is going to be able to do that. It helps to not use something terrible like lastpass or dashlane.

True if your password manager has a terrible security model, but not so if secured itself by multiple keys that never see exposure to the internet.