I have been using an Android TV app called "TV Photo" for years now and it is really great! Does exactly what you want it to do. Nothing more, nothing less.
I play a slide show of close to 50k of photos in random order. I don't think there are many people that revisit their pictures this often
Only thing I am still looking for is to automatically get my Samsung The Frame a little bit more matte and dim when playing the slide show.
Huge downside: the developer seemed to have stopped development
One of the best features of Google Photos is the ability to pull your treasured memories into a screensaver on your Android TV or tablet. But for those who prefer self-hosted solutions, here are 3 ways to set up a screensaver to stream photos from your NAS.