I can't speak for other niches, but the travel and personal finance crowd have a large number of such sites. Given that they always appear to start as "one dude

I can't speak for other niches, but the travel and personal finance crowd have a large number of such sites. Given that they always appear to start as "one dude's thoughts on travel" and turn into multiple people writing for the site, I think the answer to your question is, "you can make money at it". From your question, I think you already knowthe reason you don't hear about it on here. An Amazon affiliate powered blog doesn't have to be written in Haskell, use microservices, invent some new AI technique, and Change The World™ with a self-driving basic income. It just makes money with well-understood technologies and business models.