So many variables here tbh OP., that as you can see you'll have lots of people giving different opinions because they and their circumstances are different and we all parent a bit differently.
What time have they got to be up in the morning?
Where do you live/kind of environment?
What are they doing?
Is it dark/safe?
Have they eaten?
What's your child like with time management?
Your perception of danger
What you're comfortable with
My DD turned 12 over the summer. Getting her to leave the house has been more tricky than getting her home tbh.
During term time, I do expect her to let us know her intentions on how she's getting home from school (has a bus pass, but will sometimes get the train back with a friend).
Before the summer it was a 7pm curfew because she would have eaten if she'd been to a friend's, she'd always have some homework (although often stayed at school to do it or did it at the friends house), her time management is non existent/she can't be bothered to walk home and just stayed out hoping she'd get a lift 🤦♀️ and she has to be up early to get the bus at 7:30, so really needs to be in bed asleep by 9, so she has enough sleep.
Exception to this is Guides once a week which finishes at 9, but we walk her there and collect her, so it's not really the same.
Like most parents we do have a family app so we know where she is. Obviously it's not forever, but like I say the travel to school adds a bit of complexity and she often stays to clubs after school on a whim. I think there's a balance to be found and they'll always be one friend who can stay out until midnight, gets £100 a month pocket money, has 16 pairs of brand new trainers, the latest computer games, piercings, tattoos, gets a takeaway every night, is going on holiday to somewhere exotic etc etc. I do my best to chat to my daughter about what's going to work best for everyone, including her, so we've some kind of chance of it being stuck to - we often do pros and cons for the different options.
For context we live in a small town and it's relatively safe in comparison to other places, the place she goes to school isn't quite as nice - she's not a big fan of getting the bus on her own/without friends.