Aegis is so great especially because it allows you to set an automatic backup every time you add a new TOTP. This way, a backup is made immediately after modifying the MFA vault, stored in your phone storage, where it can be grabbed by your synchronization system of choice (e.g., Syncthing), replicating the backup on your other devices, for example. This way, you can rest assured you will always have your MFA vault no matter what.