I'm only now just starting out my on prem photo library and have a couple of thousand which sqlite with WAL seems to have no problems with.

Also considering the type of workload, I imagine photo albums to be write heavy upon photo imports but read heavy afterwards which sqlite should excel at. I'll mostly be syncing pictures from our phones, and it'll be me and the wife using it. Postgres is overkill for my needs.

What about having to do db migrations across major updates?