A search for "GZDoom" on Steam will show some different indie games that are using the engine, there are a few interesting ones.

A cursory youtube search brought up this random video with a wide variety of examples: https://www.youtube.com/watch?v=UjnOdDzSxWs

There are also several versions of random level generators for Doom engine maps out there: https://obsidian-level-maker.github.io/

I can't remember the names but there are mods and games out there integrating the random level generators.

Of course the maps are still BSP and therefore somewhat constrained but the level of creativity in the mod community is pretty amazing.