Adsense ads are not general but well targeted. The point is to get approved on hundreds of different domains!
Working for years on a domain means you are a website builder, not a domainer.
The big unsolved question is how to monetize a website that has traffic but no one wants to buy and doesn't generate revenue from domain parking.
I read a lot of good intentions or services on payment but all of them require time and/or money but i want to monetize the domain, not invest on it