Future humans realized AI was the only way to beat the aliens and sent a message to the past with instructions to invent crypto so that the infrastructure would be ready for the majority of timelines.
I thought anyone serious about mining switched to ASICs and custom hardware a while ago. At least for BTC and maybe eth, a custom asic setup is ~2-3x more profitable
BTC has been an ASIC game for a very long time. GPUs haven't been profitable there since the ASICs showed up a dozen or so years ago (with odd exceptions where power is "free").
Eth kept hitting the GPU market hard until ~4 years ago, when the network switched from proof-of-work to proof-of-stake. That cut the home-gamer hobbyist miners out rather completely.
(That last one kind of sucked for me. When my office-room had resistive heating, I rather liked getting paid for my otherwise-idle GPU to make heat for me in the winter time. It wasn't much, but >0 is more than <0.)
Ethereum switched to proof of stake in 2022. The cryptocurrency inflicted GPU shortage began in 2017. You're talking about an event that is basically a decade ago at this point.