Crypto mining has a lot of negative conotations, and for good reason. The whole crypto ecosystem is full of scammers and bad actors. And ad supported websites only have incentive to monetize more and more until they are ad infested and can only be used with an ad blocker. That's the state of a lot of the web today. Plus most big ad networks come with user tracking baked in which is another downside.
I'd rather have a nominal subscription model just to cover costs rather than see an ad anywhere. The cost of hosting per user can't be much more than a dollar or two per month. Web hosting isn't all that expensive nowadays.