That's more to do with population demographics, home size and available spending.
Even in the 1980's and in the present, families living in council estates and working class terraced streets have less money to spend on science or computer magazines like New Scientist, BYTE or in the 1980's, World of Knowledge, Insight, the dozens of home computer magazines, let alone home computers. In all probability the local newsagents and supermarkets wouldn't see a need to stock these items. In the home, there wouldn't be the space for a home computer (requiring desk, chair, TV, shelves, desk lamp) as bedrooms would be shared. Even if there was space, there are so many other kids playing out on the street that they wouldn't have the incentive to be alone. They might even be harassed for wanting to learn.
The middle classes lived in semi-detached homes, have a bedroom for each kid, or at least a large Victorian bedroom, where there is plenty of space. They'd also have the money to buy a computer, home exercise system, and all the other things like skateboards, BMX bikes, game rigs, university text books.
Those wealthy parents (and those who sacrificed their own treats) could afford home tutors and textbooks that filled in the gaps that the school textbooks didn't.
That's Britains biggest problem - the wide variation in housing designs. And it's been deliberately created due to attempts to "solve the housing crisis" by have smaller homes.