YYMV: I'm on an OnePlus 8 using the Microsoft Authenticator App. OS update changed the PIN pad, which in turn soft-broke the M$ authenticator app's PIN lock security, rather than presenting a PIN pad to enter my PIN code, it now presents a full QWERTY keyboard... making it excedingly annoying to enter my PIN - to the point where I simply disabled the PIN lock on the app (not on my phone, obviously).
So yeah, MFA fatigue is a thing and a PIN lock on the notification is not going to survive for very long given these OEM shenanigans...
Edit: Also M$ Auth app offers no proper export of my MFA keys, so I am stuck in this walled garden :')