Motivation is bullshit because it's so fleeting. You get a rush of endorphins and convince yourself that that this is it, this is the moment you change and start to improve. But once those endorphins are gone, it's back to feeling that resistance to change.
Forward momentum is what helps promote progress. As things get done, they run into the next thing, and that good feeling of progress and achievement can compound into actual results and alleviate procrastination.
Idea for an app: Random alarms during the day, and a message that just asks 'What are you doing?'. Personally, I'm pretty sure it would catch me doom scrolling or playing Tetris when I actually have something that needs to be done, undone.