GPUs were used primarily for ethereum and to a lesser extent, other shitcoins. ETH switched to PoS in Sept 2022 and 18+ million GPUs were turned off almost over night. Nothing else has the liquidity to sustain a large operation any longer. ASIC's are used for bitcoin and a few smaller shitcoins, GPUs hadn't been used for bitcoin in many years.

GPUs used for mining don't translate well to AI at any large scale. It is all newly created (modern) hardware. Some miners who ran GPUs (and ASICs) have transitioned to running AI compute (CoreWeave, IREN, NScale, myself...), but that's not the same thing as taking the hardware and using it for AI. It is new hardware.

CPUs for mining crypto are a niche edgecase with very little liquidity and generally a bad idea, since it just incentivizes botnets.