No one really mines ETH... There are way more profitable coins to mine. I dont see your correlation with GPU Mining Dying....
I got my numbers wrong last time so lets try again. Lets convert nethash to number of gpus, for simplicitys sake for example rx470
Some most popular coins amount gpu-miners - zcash, monero, etc
Zcash Nethash 335 Mh/s Hashrate per gpu 260 h/s Number of rx470 eqivalent gpus 1,300,000
Monero Nethash 250 Mh/s Hashrate per gpu 660 h/s Number of rx470 eqivalent gpus 380,000
ETC Nethash 8 Th/s Hashrate per gpu 26 Mh/s Number of rx470 eqivalent gpus 307,000
And ETH: Nethash 100 Th/s Hashrate per gpu 26 Mh/s Number of rx470 eqivalent gpus 3,850,000
So, claim that noone is mining ETH isnt exactly true.