It's really not that hard but people are addicted and don't want to admit it.

Buy an Amazfit 6 watch, has alarms, clock, health stats, memos, weather, maps, and GPS workout.

Turn off nearly all phone notifications. Do not allow any phone to AmaZfit notifications. Don't have your phone physically attached to you.

You need your phone with you? Backpack. Never in pockets.

All sudden it is incredibly easy to focus.