I think a lot of it comes from changes in parenting.
Go back 30 years (pre-screens and only 5 TV channels) and kids just wouldn't sit in front of screens for a large chunk of the day. Parents would talk to them, teach them things, play with them, baking, walks, parks, books etc... You spent quality time with your child.
It is recommended that children under 2 have NO screen time at all (including TV), yet I frequently see toddlers in pushchairs with a tablet to stare at.
Children aged 2 to 4 should have NO MORE than 1 hour a day (including TV) but some parents seem to let their kids have hours on screens.
5 to 17 year olds should spend no more than 2 hours a day in front of a screen.
I think some kids are missing out on a huge amount of parental interaction which has replaced with time in front of a screen. This is creating a massive divide between children in terms of their learning, so it is no wonder primary schools are struggling and having to fill in gaps that they shouldn't have to.
I work in a secondary school, and we discovered one Y7 pupil had managed to watch almost 40 hours of TikTok in one week.
I think a lot of parents need to go back to basics, and start spending time with their child and remembering why they actually had kids in the first place.
Most of our "naughtiest" children in school are actually attention starved and play up to get attention from a grown up as that's the easiest way to get it.