Wolf3D and Doom weren't FULLY 3D, though. The play area was 3D, but the enemies were all sprites. Games like Battlezone were fully 3D, but they use wireframe to pull it off. Descent (1994) was almost fully 3D. The map was wireframe and some of the effects looked to be sprites, but the map and enemies were definitely 3D. Thief (1998) was pretty 3D, as was Final Fantasy 7 (1997).
I'm thinking that only devs who wanted to make a 2D game were doing so by 1999. Maybe just use "Pre-2000" as a cut-off?
P.S. Funny thing is, it's only a 5 year difference between 95 and 00, but the games were advancing SO FAST back then!