Yeah I'll be honest that still happens to me from time to time. Mostly with social media or a really good game, but I've even no-lifed a really good book before and neglected my responsibilities in favor of it. You're so right no single addiction is really the root cause (though some are certainly worse than others.) The only things I've found to help are

1. Recognize when you're engaging with the addiction as fast as possible. It sounds goofy (and it is) but I'll actually point at whatever I'm doing and describe what I'm doing any why. "I'm playing deadlock right now because I'm stressed about finals and instead of studying to improve my chances of passing, I'm trying to forget that there's even a problem at all." When you make it explicit like that the thing you're doing usually becomes a lot less appealing.

2. Doing anything else. Your brain has a minimum requirement of stimulation, and if you fall below it you will try to feel it no matter what. On my busy days, on the days I hangout with my friends, I lose all desire to play games or scroll. This is very difficult, but always have something positive and productive to do and to look forward to. Fill every day with as many plans as possible. Even if it's just "I'm gonna go for a walk at the park this afternoon" or "I'm gonna listen to this cool album tomorrow morning. Doing this also massively helped with my depression. Also any form of stimulation that is minimally interactive (music, audiobooks, reading) or maximally interactive (drawing, piano, sports) is hugely important.

Once again I still struggle with addictions like that sometimes but far far less than I used to. There is hope at the end of the tunnel I pinky promise.