I suppose, that scenario just feels so far out there for me to worry about. I like being able to guarantee my family photos will not be lost.
I did actually try out Ente photos once and it actually worried me a little. It was buggy at the time, and I worried my photos would actually end up stuck in an encrypted Ente instance after a bad update.
I backup the immich directory directly onto the drive, so no matter what, even if I mess up immich, I still have my photos.