Too bad you couldn’t do something open source like that since it requires the D&D licensing.

You don't have to use any d&d system or content to make something similar (tho tbh I don't think it's a good system for videogames anyway), but especially on the content side it's hard to find a team dedicated enough and founds enough to make it happen

If you enjoyed Zero-K, there is also Beyond All Reason in development and in playable alpha state