At least as implemented in these retro-style engines, it's a technique with a lot of limitations. Crawling pervasively 2D data, in 2d grids, and grid-aligned 2d wall data, interleaved with 2d screen-aligned sprites with a scaling factor applied. Lots of vertical alignment.
You wouldn't use the same technique to implement a "realistic" 6DOF flight simulator, for example. Wolfenstein 3D released in 1992 - and a mere year later, Microsoft Flight Simulator 5 would be released, with actual 3D meshes and arbitrary 3D rotations coming much earlier.
