[sureglymop]

I think it's fine as an image format. I've used the mbtiles format which is basically just a table filled with map tiles. Sqlite makes it super easy to deal with it, e.g. to dump individual blobs and save them as image files.

It just may not always be the most performant option. For example, for map tiles there is alternatively the pmtiles binary format which is optimized for http range requests.