I agree with all those issues.

Just for discussion though: Economics don’t necessarily dominate these markets when providers aren’t informed - Uber drivers w/ depreciation for example. If your GPU is a sunk cost, and your electricity is cheap enough, it might be attractive (think consumers mining crypto back when).

A floating market rate or “surge pricing” could come into play. Outside of the top 10% of gamers by playtime, there’s plenty of idle compute during prime hours.

A secure environment would definitely be essential. SteamOS could be a great tool for that: dual boot SteamOS and make SteamBucks while you’re not using your computer.

You could only offer your machine for the titles you have downloaded. This again could be addressed by a market: popular titles could get more utilization, but obscure titles could command a premium.

No guarantee any of this would actually work, but it’d be an interesting model to explore if I were at Steam. They have hardware survey data, user activity, etc; to check viability.