You are fundamentally correct: to make your passwords safe from hackers you are making them harder for yourself to access (in this case by requiring MFA). Accessing your passwords now requires having access to a device (your second factor).
There are recovery mechanisms that you can set up ahead of time (a series of recovery codes for example), but for the most part I would agree with your premise: you will have a very hard time accessing your accounts if you ever lose your primary devices. For me the security benefit is worth the inconvenience.
There are recovery mechanisms that you can set up ahead of time (a series of recovery codes for example), but for the most part I would agree with your premise: you will have a very hard time accessing your accounts if you ever lose your primary devices. For me the security benefit is worth the inconvenience.