It's interesting you ask that, because the now-paid Kagi Search has a feature like this called Lenses: https://blog.kagi.com/kagi-features#:~:text=and%20Google.-,L...

I've found them somewhat helpful in getting rid of some of the garbage that pops up when I'm searching for a specific topic. But often, I find myself leaving them off since I sometimes want all the results on anything even slightly related because it might be useful.