Basically, my approach is to secure my home network as best I can. Insert big discussion on ad and tracker blocking, VPNs, etc. here. Pick your poison as to how far you want to go.
Then, since I trust that my home network is secure for my threat model, I simply have Wireguard on my iPhone set to automatically connect to my home network when I am not on my home WiFi so it gets all the home goodness without a whole lot of additional effort.
That won’t protect the phone against location tracking by the cellular network. Or by Bluetooth detectors in stores, etc. But that is a whole different level set of threats than the OP seemed to mention.