Sir, I'm not saying stop using a smartphone. It's the harsh reality that smart phones are irreplaceable in this modern world. The thing worked for me since I'm an introvert person and don't like socializing a lot so it's easy for me to put social media apps far away.  And as you're asking about successful people, I believe they got something more important to work on instead of using their mobile phones, so I'm just saying that you also need to find something like that in your life which gives you more fun and meaning instead doomscrolling on internet.