If you’re always available, people stop planning around your time. Being reachable has limits for a reason.

Instant availability trains people not to plan. If you reply within seconds at any hour, nobody needs to think about when to ask or whether it could wait, and your time becomes the flexible part of everyone else’s schedule. The habit forms on their side, not yours, and it forms quickly.

Pick a couple of hours a day where your phone is somewhere else: homework, practice, dinner. Reply to things afterwards and do not apologise for the gap. People adjust within about a week and most of them never notice they did.