I've stated this in another thread so apologies for repeating it.
Social distancing is all well and good in school - if you can manage it. But if you think secondary school children, who come home alone, will all practice social distancing I think you're being naive.
We had kids coughing over each other in the week before our school closed. We found kids licking book covers in our school library and we, before Christmas, discovered a boy licking a wall. All year 9 or 10, some from top level classes in our streamed school so you'd think they'd know better - they supposedly act more mature. But when friends dare, peer pressure to 'defy' all comes into it...
During the week before we closed down I had to disentangle one of our SEN year 8's from her classmate. She's a hugger. Lovely girl, but the boy she did it to hates being touched. I couldn't have anticipated she'd single him out, she hadn't before. But I had to try to explain that she couldn't hug him now or in the future. Two minutes later I had to shout at her across the room as she'd homed in on him again.
As soon as the secondary school children leave school, social distancing will go out of the window. My DS was jumped on last year by a kid 'doing a dare'. He wasn't hurt, just a bit shaken up. But bullies, kids who want to fit in with the 'gang', those who don't care will all use a lack of social distance as a way to bully, prove their worth, intimidate. They do it already, Covid is not going to stop them.
I can't imagine many parents picking up secondary school age children so drop off and pick up is a moot point for them. They're on their own when they leave that school gate.
And what about bus travelling kids? How do they socially distance in the rain, in the town centre waiting for a bus to bring them to school? At school we can, at least, ferry them from classrooms onto the bus. But at the start of the day?