That shocked me as well. Mine are 9, 10, and 12 and we've been out every day for our hour of fresh air (often more like 2 hrs tbh #rebel) and as their Mum I've made that a non-negotiable.
There is a reason the govenment have consistently encouraged those who aren't shielding to go outside for daily exersize; it's really vital for your mental and physical health.
I don't want to be too judgemental, but there's no sugar-coating it sometimes, and to oversee a teenager not leaving the house for approx 7 weeks (without any particular reason) is piss poor parenting by anyones standards.
I have no doubt that if allowed, my kids would sit on gadgets all bloody day, and always decline fresh air(!), but I'm the adult in the relationship so I make suee they get their fruit and veg, fresh air, academic input, emotional support. I mean
duck me I ain't no Mary Poppins but 7 weeks of staying inside