@pharmachameleon I agree with a lot that @Araminta1003 says. I just ensured I facilitated organisation and an expectation of commitment to education. I came on MN way ahead of them starting secondary and read up on how other parents helped to organise their children. We implemented some systems at home to give independence, daily tick list, homework chart to record it on a noticeboard so visible to them and us, timetables in several places in the house, bags emptied when they came in put into labelled magazine files for the next day they needed them. Bags packed the night before so no last minute rush. We had a homework time slot at home, all homework was to be at least started, if there was no homework they could watch youtube but it had to be something related to what they were studying in school. Instead of how was your day, they talked through each subject, just brief ie maths we did angles in triangles sort of thing. It meant we could widen discussion on their topics at the family dinner if needed.
I know you said he would much rather play on his xbox/phone I mean who wouldn't but this leads to a conversation about the fact that you don't live with your parents, he won't live with you forever, you want him to earn enough money to pay for the latest console and phone and that comes from a well paid job. Look ahead at sixth forms for grades on entry, some subjects for A levels want certain grades. Maybe even look at a university and their entry grades. Look at apprenticeships, jobs, salaries, house prices, mortgage calculators. I know this seems crazy but the earlier you plant that seed the better. School will end, it is short. I am totally for hovering over any child to help them academically. Does he understand the grade curve and how some parents are paying thousands for their child's education? The playing field isn't level.
The state school we sent our children too was incredible, well above average progress 8 and I have to tell you what the school did. They had an amazing open evening at the start of year 7 about sources, ie where you look on the internet for your information for homework for all subjects but it was put on by the History department. They literally had you (parents and children) go through 4 different rooms and listen to 4 different sets of testimony about a Victorian murder victim. Imagine a "body" laid out (year 11 drama student) under a sheet covered in blood, they give you results from the coroner using the body to show bruises on the arms etc, next room is the bar (again filled with drama students dressed up) you hear the testimony of one of the bar wenches, next room, police station, you hear the police report, as you make your way to another room there are drama students singing who will buy my sweet red roses from Oliver, carrying baskets of flowers. Amazing. A witness tells of seeing someone running from where the body was found and a description of the person. At the end the staff talk to you about reliable sources and those that are not as reliable. They also did other subject open evenings over the years to help the children.
The school did everything they could to make a child succeed so we did the same at home. My children have now both finished secondary school so we are on the other side of this. The higher the GCSE grades the more choices they have for the next step.