FYI, you can put a 2FA secret into Bitwarden and autofill the one-time passwords alongside the regular password. That would mitigate the impact of losing your phone.
And if I lose my phone, I only need to do the recovery flow with the printed codes for one account, rather than for all of my accounts.
Grandma, and Uncle Rob, and your cousins, and anyone else you have a long standing relationship with, can use your VaultWarden instance if you let them.
But! You now get to maintain uptime (Rob travels and is frequently awake at 3am your time) and make sure that the backups are working... and remember that their access to their bank accounts is now in your hands, so be responsible. Have a second site and teach your niece how to sysadmin.