Perhaps we could overturn the third party doctrine. With legislation, preferably. And while we are at it, solve the underlying issue of pervasive data collection and sharing in the first place.

Another angle I think worth attention is product developers should build tools / platforms that don't even touch user data and be open about that so consumers can choose those more. I believe people will choose privacy when given the choice more often if the product is just as good or better.

This is what F-Droid does. However Apple doesn't allow you to use it, and Google is slowly following their lead, too.