I remember when Voxels were the "Next Big Thing", 20 years ago.

Delta Force:

https://en.wikipedia.org/wiki/Delta_Force_(video_game)

Which used the Voxel Space engine:

https://en.wikipedia.org/wiki/Voxel_Space

What was/is holding voxel back? the new programming model? computation density?

I guess minecraft is an example of a voxel game (supposed a voxel game written in block style according to a random post on the internet[0]) that became really popular -- so I guess the answer could be "nothing", but it sure seems like voxels are still niche (and don't want to be).

[0]: https://forum.unity.com/threads/voxel-games-vs-block-games.2...

The „Voxel Space“ engine from the 90th has only very little to do with what we call voxel today. It it basically a raycasting engine for height maps [0]. It is very limited. You can‘t look up and down more than 20 degrees and you can‘t even render houses, cars or trees.

[0] https://github.com/s-macke/VoxelSpace