That's fair. And in the case of Immich, the photos are automatically backed up to my computer so if I lose my phone I don't lose the images, but I totally understand wanting something exclusively on the phone (Immich can let you browse photos local on your phone, but I don't think it indexes them for searching by person/object). Unfortunately I'm not sure something like that exists, especially since the machine learning for identifying people/objects in pictures is pretty computationally intensive.
I wish you luck in your search! I agree that would be a great app to have

Beets is one solution, and I also recommend taking a look at Musicbrainz Picard. It's a more graphical and user friendly way (though more manual) to identify, organize, tag, and sort music into a preferred format. It's what I use on all my Bandcamp purchases to clean up metadata and add things like lyrics before it automatically throws it into the right folder