I have a 15 year old and a 12 year old, both boys.
Ds1's mobile is next to me because he is 15.
Rule is 9pm cut off for all tech for him. He then reads for a bit before going to sleep.
He understands we pay for his mobile phone contract, there are rules re tech and family time which includes meals are eaten as a family, no food in your bedrooms at all or drinks unless water.
Homework is to be done when they come in from school and then they can game. They are both outstanding students so are allowed to play for 1hr 30 mins before dinner. I am a SAHM so am here to monitor it all.
On weekends they do play more but again as long as homework is done and chores they are free to do it. But we do play games as a family, watch tv and films together and they do an extra curricular activity 2 weeknights a week. So there is some balance.
Ds1 has taught himself guitar and rubix cube for fun. Ds2 is using a computer game to learn engineering skills and watches educational science stuff on YouTube. So there is balance.
It is shit being the parent who says no. There are no 18 rated games in the house, they go to bed before 10pm when all their mates are messaging each other until 2am but they do know that we care about them enough to be checking these things.