Do I have to delete the apps forever?
No. The point is to break the automatic thumb path, not to prove something. Plenty of people reinstall one app after a month and find the pull has genuinely gone.
What about apps I need for work?
Keep them, but strip the feed: turn off notifications, use the browser version, and give yourself a fixed window. The problem is rarely the app, it's the infinite part.
I scroll because I'm anxious, not bored. Does this still work?
Partly. Friction still helps, but the replacement matters far more — a walk, a call, writing the thing down. If the anxiety is the engine, treat that directly rather than blaming your screen time.
Is 30 days long enough?
It's long enough to break the reflex and see what your evenings are like without it. Whether it holds depends on whether the friction stays. Most people who relapse do so the week they put the app back on the home screen.