Photoprism has superb performance - I have no lag going shifting through many, many photos.
Nextcloud lately upgraded their gallery, but it is still slow. It generates thumbnails on-the-fly. Maybe I can configure it somehow (I tried for v1 gallery but failed). Anyways, Photoprism is great and works out of the box. I like that I can select photos from different folders/views and do with selected photos something (like add to an album).
Moreover things works (Except delete, but archive is OK) for readonly volume, which is handy to mount nextcloud folder.
However a thing to note - you cannot use RPI4 with 2GB to use AI features - at least I had many other services running and RPI was lacking. But viewing photos was still good.