My mum was a stay at home mum for some of the time but would quite often go off and get a part time job which would mean us letting ourselves in after school. The key was always left hidden in the shed. We weren't on our own for long & we had good neighbours we could go to if there was a problem but we were fine. I quite liked it, I used to make a cup of tea for my mum ready for her coming home from work, using a kettle on the stove, lighting it with matches!
We also occasionally sat in the car while my mum and dad went in the pub for a drink, kids just weren’t allowed inside in those days. My dad used to bring a bottle of Coca Cola or sometimes orange or lime Corona & a bag of crisps or peanuts out to us. If there was a pub garden & the weather was nice we’d all sit outside. I used to love it either way.
My mum was definitely a latch key kid, her dad was away at war and her mum worked all hours on a local farm. Elderly neighbours looked out for the kids, just how it was in those times. I think we were probably all much more independent and very capable of fending for ourselves back then. I wouldn’t have dreamt of allowing my DC or now my GC to do the same though.