I have definitely seen articles suggesting drug taking is down from, say, 2010 levels- but that doesn't mean that taking drugs isn't still very common.
I was a teen in the 2000s, as the internet, social media and mobile phones were becoming more prevalent. I do think these may have made getting hold of drugs easier. Before it was made illegal, in sixth form, some of my friends would buy M-Cat online and it was easier to buy than alcohol! Aged 16-18, I would say there was M-Cat and weed at every party, and I could certainly have gotten hold of harder drugs if I'd wanted to.
At uni, MDMA was everywhere, and coke was pretty easy to get too. We also used to take Valium to help us sleep after taking coke, or to help with the effects of a come-down. Ketamine was really common too, and I think a bit worse than the others as it seems more addictive.
Anyway, I'm not saying this is ideal, but most of the people I know who were taking these things as teens or at uni are now successful and productive adults. I do think they can make existing mental health problems worse, and the people I know who ended up having "drug problems" usually had histories of mental health issues in their teens.
However, since graduating, talking to other people in my age group, it does seem like a bit of a friendship group thing, and perhaps more common in rural areas where there is less to do? Plenty of people aren't touching these drugs at all- ever. So I think if your children are in a group/school/town where this stuff is common, it will feel like it's everywhere, when in reality, it's not.
Part of me is in favour of regulation, because I have seen people who've ended up in hospital because their MDMA or Coke was cut with something nasty. Also, I do think, in general, these things are less harmful than alcohol. There are a lot of ethical issues with drug production, which could be tackled if drugs were legalized.
However, with drugs like M-CAT, I did see a difference in circulation when they were made illegal, and I do think drugs can have really harmful affects on a minority of individuals, and in some cases there is a big risk of overdose.
I also think part of the "fun" of drugs at uni was the thrill of doing something illegal, a sort of feeling of rebellion and being "in" with a sort of secret club. So if less dangerous drugs like weed were made legal, we might have sought out something harder?