Thanks @incognito50me that's it, really!
And funnily, in my teens' circles, the dating / kissing thing is happening later too.
In my case, even tho I was a desperately shy geeky teen, the only entertainment was to go to these godawful GAA discos in random clubs around the countryside. The only thing anyone did there was kiss!
I hated it. But did it. (Peer pressure).
My 16 yo DD has had no interest in discos but does way more interesting thing than I ever did. She goes for coffee in mixed groups, cinema, food, hill walks, swimming & plays loads of sports. My 14 yo DS similarly does loads of sports, and hangs out with pals but mostly boys. Some go to discos, some have kissed girls, he's said he's not ready. To be honest I expect that to change shortly enough, and hopefully he'll have enough sense to make good choices as he hasn't a dither of wit at times.
But in both cases it's happening quite a bit later than my youth, even tho I was a million times less cool.
It's all very much contextual I think. The other difference is their willingness to discuss 'cringey' stuff with me. Not even the sex-stuff, per se, just the awkward fancying someone / how would I kiss them / what would it be like / what if .... kind of stuff.