Mining hardware seems to have become an arms race. I expect some of it is only used for a short time before it becomes un-economical to run. You have to hope it paid for itself in that time. Those with access to cheap electricity stand to make the most. I expect the cloud mining rigs are in places where it's cheap.

I'm trying some Steem mining on my PC, but it's probably not really worth it for the tiny amount I'm likely to make. I'm just interest to see what happens. It looks like a few people are getting most of the blocks. They must have access to a lot of PCs.