The two criteria I suggested were “not saturated with ads and AI trash” (technically just the latter would satisfy OP’s problem), and DDG meets both of those with no problem. Its AI “assistant” and its ads can both be trivially disabled. I use DuckDuckGo because I love its frontend and because it gives me fewer problems than Google did. I’ve only ever used alternative search engines that piggyback off the major ones (as you listed: DDG, Startpage, and SearX), so someone else would have to answer that for you.
The two criteria I suggested were “not saturated with ads and AI trash” (technically just the latter would satisfy OP’s problem), and DDG meets both of those with no problem. Its AI “assistant” and its ads can both be trivially disabled. I use DuckDuckGo because I love its frontend and because it gives me fewer problems than Google did. I’ve only ever used alternative search engines that piggyback off the major ones (as you listed: DDG, Startpage, and SearX), so someone else would have to answer that for you.