Ask HN: Privacy-focussed OnePlus 6 – how much can be done?

I have an old iPhone 6s that I may need to upgrade in the near future. I am not that impressed with the line-up from Apple, and somehow OnePlus always tempted me.

The real issue though is privacy. I won't be dealing drugs from the phone, but I do not like being watched and that has kept me from Android phones. But how much can be done? How much can you detach it from Google-surveillance?

I do not know if the advice would be specific to OnePlus 6 or 6T, but just included that information as it is the phone I am most tempted by.