Why on earth ppl do this, Just typing in the numbers for a Radeon Vega Frontier Edition you see you get perhaps a dollar a day profit, since they cost $1000 you'ld have to run the thing 24/7 for nearly 3 years to just break even.
Thats if the thing doesnt crap out in the meantime from being pushed for so long and hard. Perhaps you can sell the card afterwards if its still going, just don't mention its been running 24/7.
I'm not factoring in the other stuff, extra hardware/power costs your time and effort. WTF would anyone in the west do this? Sure I can imagine a case if you're doing this wholesale with 100s of of cards but a person at home on their PC