Exactly. If dumbphones made a comeback, companies would simply achieve it by presenting the user with a dumb UI while the data harvesting would still go on in the background.

I guess there's the valid argument that you'd be doing less on your phone so there'd be less to spy on, but there'd still be spying, and much of it would simply be shifted to the user's PC instead of a smartphone. Guess what, spying is rife there too.

The answer to stopping the spying is privacy laws that put people, and their privacy, above tax-dodging multinationals.