Do you serve the ads yourself or do you defer to third party ad networks? I have no problem with the former, but with the latter I think it's very hard to control what gets displayed, and you're also opening your users up to various attack vectors.
There has got to be a niche available for somebody to do plain old non-evil advertising???
EDIT $15,000 a year sounds like a tremendous amount of money to run a web site in 2019 ...