Companies like 3DFX (which once one of the best and very notable with their GLIDE API) got bought by nvidia. Imagination Technologies (IMG) left the PC gpu market to focus solely on mobile gpu (Power VR series). on mobile there are still plenty company making gpu's like IMG (Power VR), Qualcomm (Adreno - which originated from ATI mobile division), Nvidia (ULP Geforce), ARM (Mali) and Intel
There are VIA motherboards with build-in CPU and GPU for one (I had one of these for a small NAS, which could have been used for a very lightweight computer as well).
Raspberry Pi and stuff like that use other brands of GPU as well.
mobile phones in "request desktop site" mode? That's a wild guess.