I have two boys with sn and I mostly post on the SN boards, but that's mostly because I'm dyslexic too and don't enjoy people take ing the piss pointing out spelling mistakes.
I think as said before, diagnosing the issues is better than it was when I was a kid. You was just naughty, stupid back then. I'm sure the boy who threw chairs with the force of a adult at seven had ADHD. But he was just a terrible, naughty child with bad parents back then.
I do see stats that ASD is on the rise, not sure if it really is or people are just better spotting it.
I have been waiting 5.5 years for a ASD test for son. So in my experience, it's a very very hard diagnosis to get. Drs want to be sure. My toddler was diagnosed and we had the "talk" about whether or not we wanted to proceed to a diagnosis. So for me, I had the choice to not get him diagnosed. I didn't want to wait another 5.5 years so we went ahead.
Btw he's 3.5 and has no words at all so it is ASD and he's not "stupid, lazy" etc but I suspect he's also quite naughty at times, like all three year olds.
In 550 kids in my older boys school, only three have SN provision at the statement / EHC level so that's not a massive % of sn