I don't know if this complaint is valid and what the exact scope is. However, since switching to Safari and iPhone, I no longer constantly need to be on the alert about my privacy.
I strongly believe that Google's business model will always push them to exploit my privacy if there is an extra buck to be made.
1. Firefox used a lot more memory & CPU on my MBP. Maybe that is fixed now. I remember reading that they worked on the footprint.
2. The large majority of Firefox's revenue is (indirectly) driven by ads from Google. I just wanted to get out of the ad swamp once and for all.
I guess I could still be tracked based on IP address as I'm not normally using Tor. Ublock and Privacy Badger does help there, I guess, but while it's not foolproof I do believe it's better than just assuming that Apple will take care of privacy for you.