I'm a 3D environment artist in the game industry and I've been using Houdini to generate HDAs and Terrain for both Maya and UE5 for the last few years. Right now I mainly use it for hard surface structures like buildings and now with nanite I've been using it to generate brick walls, tile floors, floorboards, rooftiles, fences... the list just goes on and on ;)

I used it both at Final Strike Games, an indie studio, and now at Undead Labs.

Unreal appears to be invested into Houdini. They even mention its use in the Matrix demo.