I image affects like many of lockdowns will be uneven.
I'm not sure my teen girls were affected the same way and they had easier time than DN as Dsis had money issues, serious work demands no childcare for younger child and a relationship breakdown.
They also had two parents at home and siblings perhaps somewhat mitigating loneliness and isolation - we ate together every evening and lunch and spent evenings together much more than now. Some of DD friends were home alone a lot due to parents work and much more isolated or other's who had very difficult home lives and even in exam years very limited access to online ways of staying in touch.
Also on MN some say it was just a few months - DD2 it hit end of Y6 and here in our bit of Wales it was Y9 before there she has a "normal" school year again.