You don't need "infinite" willpower. You might even need very little once you've changed into a default mode of using your phone less. By the way it's still unclear whether ego-depletion is a real phenomenon AFAIK.

I'm noticing that for me, simply disrupting the pattern does wonders. A background process that re-bans websites via localhost redirect in my hosts file every few hours does wonders, for example.

A bad habit I can fall into as easily as breathing is a problem.

A bad habit I have to indulge in some effort to perform, puts me in the position of needing willpower to indulge in it!