For what it's worth, I think I did a reasonable job of this. I don't consume any web-based algorithmic feed content and participate in nothing interactive other than Hacker News and do not visit Hacker News every day, or even every other day most of the time. Almost never on weekends. It's really an "I'm bored at work" thing.
As others said, I had to replace these things with something else. I'm not meditative enough to just sit around with a perfectly still mind staring at the wall. For me, it was a few things. Books, first. Not hugely consistent with what they're about. First few years was mostly sci-fi and fantasy, then a year or so of non-fiction pop physics books. Right now, I'm mostly reading cooking books and learning to cook better. That's the second thing. I cook all of my own food, from scratch, and experiment a lot. That consumes quite a bit of time and it's active time. Third, music, but not algorithmic feed music. No YouTube music or Spotify recommendations. Nothing social. I'm listening to complete albums, curated either because I'm in my 40s and already know a lot of music I haven't listened to in a long time, or via human critics the same way I curated music in the 90s. Fourth, movies, but again, nothing algorithmically generated. Just like it's 1999 again. In fact, Alamo Drafthouse is doing a celebration of 1999 for its 25th anniversary. It happens to also be my and my wife's high school graduation year, so a lot of beloved movies to go see. At home, we're doing 70s. We've gotten through Easy Rider and Rosemary's Baby (yes, I know, they're 60s), Badlands, Days of Heaven, Dog Day Afternoon, and Harold and Maude. Quite a few more to go, queued up and ready, curated from prior knowledge. I've already seen most of these but my wife has not. Fourth, exercise. You can't just get off the couch and do it. I spent years building up the capacity after spending the latter half of my 30s mostly inactive due to degenerative spine problems. Started off with resistance bands and walking 6 years ago. Today, I lift for about an hour 6 days a week and then run, row, or both for cardio, anywhere from 60-90 minutes a day. Fifth, concerts. My wife and I saw Judas Priest and Dead Kennedys at the end of last year, Tool last week, and we've got Madonna, Social Distortion and Bad Religion, Ministry, Echo and the Bunnymen, and Slowdive scheduled over the next few months. We usually travel to a multi-day festival or two each year as well but haven't decided which yet for this year. This is also curated from prior knowledge. I guess I miss out on whatever is hot right now, but oh well, there was plenty of great music already out there in 1995 and plenty of these acts still tour.
All in all, this gives me goals, accomplishments, scheduled events, social interaction with a real, non-anonymous person I actually know who is physically present, had made me far healthier, more fit, and better looking, and the quality of my entertainment, though I suppose less "addicting," is much higher.
The downside is this is expensive, but it probably doesn't have to be if you actively bargain-hunt, stay local, work out at a gym instead of buying your own equipment, and eat worse than me. Probably many people on the Internet would say another downside is I'm not very tuned in. It's an election year and I have no clue what any candidates are doing, saying, winning races, and I probably won't vote. Oh well. I'm sure the world will do about the same as it would have done if I didn't exist, which is fine. I'm not that important and neither are you.
Edit: I guess it's worth adding none of this involved or required getting rid of my phone. The phone is, in fact, quite useful. I listen to my albums on it. I buy movie tickets and concert tickets through it and they're delivered to the phone. I buy airline tickets and keep them on the phone. I keep my recipes, log my food, log my workouts, and map my runs on the phone. The local train system sells and keeps passes on a mobile app. There is nothing wrong with phones per se. Just don't let these apps gamify shit for you. Don't opt into social features. Don't create an account if they don't force you to. Disable all notifications. Don't worry about what other people are reading, where they're running, what they're eating. Just worry about yourself. Don't have or use any pure social apps. No algorithmically-generated content feeds. Read full-length novels, watch full-length feature films, and listen to complete albums. Force yourself to exercise at least a medium-term attention span. You don't need a change of theme every 40 seconds.