There are few open source projects coming along that let you sell your compute power in a decentralized way. I don't know how genuine some of these are [0] but it could be the reason: people are just trying to make money.

0. https://www.daifi.ai/

There have been countless projects to sell distributed compute power. I don't know of any that have gotten much traction. Everyone keeps trying to create new ones instead of developing for the existing ones.

The one you linked to looks clearly like a pump-and-dump scam, though.

That one definitely looks like a crypto scam.