In the case of DD2 & DD3, their school costs between £73,000 and £103,000 per year (some pupils will have 2:1 support, some will have therapy costs, etc).
Every student has a bespoke timetable with a curriculum that meets their ability and aspirations. So some will be studying English GCSE, some Functional Skills 2, some Functional Skills 1, some Entry Level, etc.
Every student gets 1:1 support at all times throughout the day. Staff hand over their student to each other throughout the day. A few students have 2:1 support at all times.
Every student has 1:1 teaching. So they get their own lesson in maths, say, covering what they need to learn in the way they need to learn it.
The classroom environment is adapted to their style of learning each time. For example, DD3 doesn't like bright lights, so the school bought a reading light for her and her English teacher turns the lights off and uses the reading light. For another student she'll turn all the lights on and play background music.
Students can do their lessons on site, off site, in the community, etc.
The staff have pool cars that they can take, so they can meet students at home if they can't come to school. DD3 had OCD and a traumatic school experience, so the staff spent almost a year driving to our house and sitting on the driveway. At first they were at the bottom of the drive, then they worked their way up the driveway, then they were able to sit at a table outside the front door, rain or shine, then they were allowed in the porch, then the hallway, then the lounge. After 9 months DD3 was able to visit the school site for a few minutes. She now has 100% attendance.
DD2 has attended since starting but finds a full time timetable overwhelming and doesn't cope with the taxi journey. So staff pick her up and drop her home each day.
That sort of provision costs a lot of money but for many of those children it's giving them the foundations to be productive members of society in the future.