I use Google DNS because it’s fast and reliable, and close to me. I’m not sure what else I’d use that’s more trustworthy. Certainly my ISP isn’t.

Their DNS privacy policy seems acceptable to me, as they’re not using it for ad data: https://developers.google.com/speed/public-dns/privacy

Google obviously has many concerns, but they’re trustworthy enough to follow their own privacy policy lest they get smited by governments.