Frank, just read your long post upthread.
You sound a very sane, balanced parent. I also had ishoos with the safety police at my DCs primary school. I dared send DC3 (then 5, incredibly sensible and astute for one so young, and dead keen on getting into her classroom as soon as possible) up the drive with her elder siblings. I was 99.99% certain that she wouldn't come back down, and 100% certain that if she did, someone who knew her would field her and point her back in the right direction (there were always people chatting on the pavement long after the bell, anyway).
That was Not Good Enough. I had to escort her to the door of the classroom: not the school gate, not the infant play area gate, the door.
I could have accepted the playground gate as a compromise (to which some parents tenderly escorted their 11-yr-olds) but I thought the door was lunacy. I probably said so, since I felt it important that the school should know that not every parent thought its policies were 'all for the best' and 'to keep our little ones safe'.
The point of growing up is not to be 100% safe. It's to learn to deal with the very not-safe situations adult life will throw at you without anyone to help you. Some of that learning you can do under the eye of a parent or other carer. Some of it, thb, you can't. Things like, Is this road safe to walk down alone, now, this evening? If you have practised making that kind of assessment with your friends on the way back to the station from the cinema at 16/17, you are better equipped to make it at 18 and suddenly stranded in a university town, than if your parents had always collected you from said cinema by car.
It's about learning to make your own decisions rather than either expecting to look for or receive guidance.
And it's also about freedom and having fun.