Because social media exploits the same mental addiction as gambling, “retail therapy,” and adrenaline and exercise addiction. You may as well tell a caffeine addict to just stop drinking coffee every morning and cut chocolate out of their diet.
This is something that people who have never experienced mental health issues like addiction struggle to grasp because they’ve never had the wiring in their brain used against them by companies like this. It takes immense willpower to fight against the physical makeup of your brain and not fall to the temptation of reinstalling social media for the endorphins.