I believe the point was that the types of ads or surveillance we are talking about here doesn’t strictly require 5G. It can work perfectly well with existing 4G/LTE networks and infrastructure. You could send a pretty good signature of what someone is watching by SMS if you really wanted to. The components to add that connectivity to consumer electronics is not that difficult or expensive to add from a BOM perspective.
I think the reason why we haven’t seen more of this vector being used isn’t because it is technologically unfeasible, but rather that there are easier ways to get a device connected.
I think the reason why we haven’t seen more of this vector being used isn’t because it is technologically unfeasible, but rather that there are easier ways to get a device connected.
This is true, but it's also something that right now consumers can at least do something about if they are well-informed, as noted by many commenters here referring to not allowing "smart" devices access to home WiFi networks and the like. I think the danger with 5G, and I'm including the surrounding culture and marketing under that umbrella here, is that the channel for remote communication becomes independent and so potentially impossible for consumers to detect, monitor or prevent, even if they are otherwise relatively well-informed about the technology.
I think the reason why we haven’t seen more of this vector being used isn’t because it is technologically unfeasible, but rather that there are easier ways to get a device connected.