They became part of bigger open world games like Fallout 3, with only a few being made afterwards like Singularity and the later Wolfenstein's, then came GTA online and all the money made of MTX and Gaas games that the companies wanted especially Bethesda,, so now its just Steam games like Robocop and Terminator Dark fate that really carry the torch, other than Doom of course, but i wasn't impressed with the latest Doom, they were great games back in the day Fear 1, Half Life 2 and Crysis 1.