I admit I think once your DC are working full time, they're walking down the path to adulthood. I also would hope parents keen on rules, have had a situation where each child does various tasks to help around the house.
It makes sense to have a curfew, as some parents are keen to lock up & get the alarm on. At the same time, exhibit flexibility, so if DC is going to be later, as long as they let the adult know. I can't see why them having the odd night out would be a problem.
I also think from leaving school to going to college/uni/work, you're still a parent, you still have some obligations to fulfil. So money management, how it all works with credit, why you should save, why waiting to pay for something with cash is better than a store card, why bills have to be paid on time. Then life skills, so make sure DC can cook, clean and tidy adequately. Think of it as passing on what you've learnt to make life easier.
I did used to think schools should teach life skills, now I've done a u-turn and think it's important to instil certain standards into DC. The idea of going to uni and only being able to cook beans on toast is awful.
It's finding medium ground between doing everything for DC & the opposite of that.
Even with younger children I'd like to think they are guided over ruled. To me 'rules' show a parent who loves the associated power.