Well at the beginning of the pandemic, for quite some time, if you might remember, they were very much kept indoors, except for going out once a day for some exercise.
They have been in touch, online, of course. That's not really the same as a normal teenage life, is it?
Once allowed, yes, they have met socially distanced - those who weren't vulnerable and shielding, or with vulnerable and shielding family members.
While you and your marvellously mentally robust family (Christ I hope they are, for their sake), may have sailed through this without any negative impact to mental wellbeing, perhaps you might want to realise we're all born different, with different personalities, with different pasts, different presents, different family structures and supports, and for others, it might be a lot harder. And that says nothing about them, nor about their parents. Except that they might find it a lot harder.
And while not indulging wallowing, it's okay for parents, children, (and teachers!!) to say that they've actually found it all a bit shit, they're a bit fed up, and they rather hope that they can get back to a bit more normal normal soon, if it's possible.