Niche knowledge sites don't use a lot of bandwidth, and in a lot of cases can easily survive on the donations of niche knowledge fanatics (especially after the rise of patreon and substack.) The real niche knowledge sites who can't survive without advertisement are trade magazines, and if the ads are specific to the niche (rather than generic intrusive ad auction chum), their readers value the ads almost as much as they value the content.
Most niche sites I know are completely ad free. What are some that live off ads?
Goodbye, 99.9% of content we all regularly read.
Speak for yourself.
Do it. I dare you. You won't take your site offline, nobody else will either.