Do you think it's more than 5%? Maybe it is, but it seems like every place that offers GPU rental services (Amazon, Vast, etc) they are being used almost exclusively for machine learning applications. The rate they can be rented out is 3-4 times higher than would be profitable for any cryptocurrency mining, which should be a pretty solid indicator of where the demand is actually coming from.

I know I'm in the minority, but my GPUs are used almost exclusively for password cracking. I've got ASICs for the crypto mining.