pretty much. DDG for example uses a bing-yahoo “alliance thing” (can’t remember what it’s officially called but Microsoft and Yahoo have a sort of partnership in this regard).

Your options for actual first party search options are literally pretty much the ones you listed. Yandex is russian so not trusting those guys anymore than I trust Google or Microsoft so that just leaves Yahoo which is…yeah.

Honestly people are just better off using something like SearX or 4Get. they’re all the same except with those two you’re not going to get the AI slop or ads.