ETH is not a concept how to make use of GPUs, its a concept to replace current business contracts and the inevitable subsequent court cases that happens when one side is not happy with something they had previously agreed to, ETH is about the creation of a blockchain smart contract system, just imagine how the Twitter - Musk sage would look like had that agreement been signed on some sort of a ETH smart contract.
ETH is light years away from getting to its goal, ETH still lacks a robust infrastructure and a trustworthy ecosystem, one of the major hurdles for ETH to overcome was the excessive GPU power it used, mining was a ridicules system and caused severe limitations so the ETH developer team worked extremally hard to switch over to a PoS based blockchain, its hard to conceive that some serious blockchain developer will ever go backwards and build a PoW based system.
yes, some people found ETH mining to be interesting as a side hustle, but they were not part of ETH, they were acting for a while in a critical role as the enablers of the ETH infrastructure, but they were never a real part of ETH, since ETH was never designed as a system to make use of GPU mining, and its hard to see that enthusiastic GPU miners will find it lucrative to build a entire blockchain system just for the purpose of GPU mining, blockchain needs to have value in order for the miner to cash out their earned coins, and the value of a blockchain was never in mining.
As a side note, unrelated to the above; ETC was just removed from Coinbase for the reason it lacked interest and had no activity on Coinbase.