Most teachers I know want to get back to school and back to normal, the thing which is stopping this is the social distancing. Due to the size of most classrooms, the maximum number of children they could fit in would be 10 - so for your average class you need two extra rooms. That is why in primary schools years 2,3,4 and 5 can't return yet, there just isn't the room. So getting schools to return in August, unless the social distancing has reduced, still wouldn't be possible and some people doubt if it can even be managed for September. It may be a case that children will have to attend alternate weeks, which will be hard for parents who have to work.
As schools closed in March, I still can't see why those taking GCSEs and A levels weren't allowed to take them. The pupils could have been spread across all the empty classrooms and halls, so would have been well distanced.