I use Bing because it gives points at ~$5/month from letting it spy on you. Microsoft doubles their points to $10/month when you send to a charity. Using Bing vs technically/privately better options gets ~$120/yr sent to the FSF. I asked FSF and they validated that they get what MSFT says they send.

Regarding more privacy-marketed search engines, I perceive the privacy argument from corporate search as marketing. Any corporate search engine should be selling your data to maximize profit, even if you pay monthly.