2FA isn't the end all be all if it can lock me out by losing a device or an arbitrary number I dont actually own (e.g. sms 2fa)

With a password manager, keeping track of 10 passwords is barely any more effort than one user account. Same thing is true for 2fa secrets.

Use authenticator apps or things like yubikeys for 2fa, using your phone number is not a security benefit but an exploit waiting to happen at this point.

And the day the "master" account gets suspended or compromised you lose access to 10 other accounts. No thanks.