GPUs are already too expensive for gamers and now you want to do this?!
It's kind of overblown. If you run well within the temperature and power limits they are still usually good for years at 24/7. Usually they run a bit hotter or slower because something has evaporated or slightly worn out, or maybe a fan died that needs to be replaced, but otherwise are fine.
If you are lending out your own GPUS presumably you can set a reasonable power and temperature limit.
I would love to let my 1080 Ti be put to use when I'm not playing games on it, cryptocurrenty mining was fairly profitable until a month or so ago and now the power usage (even at $0.10/KWh) isn't covered by the returns after paying the tax bill (I could always file the revenue under my LLC and deduct the electricity expenses and even deprecate the hardware cost, but without a dedicated rig and power monitoring it's a tax audit nightmare waiting to happen).
The fans are in a bit worse shape, but those tend to be easily replaceable if they fail.
Side note: AI research is more beneficial to society than running a few instances of Crysis 9 at 4K 120HZ.