In densely populated areas, the logical endgame is for devices to create their own mesh networks, independent of any active networking you might provide to them. Then all it takes is any path from your device to the mothership for your data to leak.
Homes with built-in Faraday cages and their own internal repeaters with firewalls for signals you actually want to let through is one possible technological response, but obviously worthless the moment someone creates a path outside the cage, for example by ever leaving the house.
A more practical alternative would be finally passing laws to regulate this area and protect privacy in meaningful ways in the context of 21st century technology, while still allowing beneficial applications of these technologies for those who don't want to be digital hermits. Given the modern reality that even if you opt out of everything those around you might not, the most reliable ways to prevent abuse of data by corporations are to ensure that it is not profitable to do so and/or the executives responsible for setting the policies will go to jail as a result.