Speculative, but I think that draconian measures only backfire when the parent-child relationship isn’t trusting and loving in the first place, i.e. if you’ve given your kids reasons to hate your parenting beyond your restrictions on their screen time. When I was a kid I had friends who were pretty strict about their internet access, but they did not mind because they have a good relationship with their parents anyway—they play sports together, share interests, work on the same hobbies or weekend projects, etcetera. Maybe this is what today’s millenial parents are lacking in, in the first place.