I feel like simply setting an age for these things doesn't really do much good. A lot of people will be ready for emancipation before that age and will simply be hindered by an arbitrary amount of time; while others won't be ready and could potentially lose the care they need because of it.
I think one idea could be that there is a test available to all minors over 13 years of age that allows them to prove their maturity and ability to take care of themselves, and thus emancipate themselves on their own terms.
In addition, at 25 years old if a person is not yet emancipated they should be given a mandatory psychiatric examination to determine if they are disabled, and if so put them where they will receive their needed care; and to otherwise emancipate them so they are forced to start caring for themselves. Part of the incentive for people to emancipate themselves as soon as possible, and to therefore stop leeching resources from where-ever they are getting their care, is that all their legal limits are lifted once they are emancipated. They can't drink until they emancipate, they can't smoke until they emancipate, they can't drive until they emancipate, can't (legally) view/buy/participate in research until they emancipate, they cannot get a formal job until they emancipate, and they cannot check the box to accept the EULA until they are emancipated.
Anyways, that's just a concept I thought would be interesting.
the problems with this are that, for one, tests are expensive to create and administer, and it would probably be a pretty large obstruction to a lot of people gaining the rights that they're entitled to. making the test would also be difficult because there isn't really any way to quantify maturity. you can test different basic cognitive skills in theory, but at that point you're secretly just having an IQ test to unlock your freedoms, which sounds like a pretty sketchy idea to me.
in addition, if the test is in english, you're excluding people who aren't fluent in english, either because they're still learning or never had to learn. the whole idea would also seem to imply that people have to
earn their legal rights by proving that they're worthy of them, rather than automatically gaining them. this would be an incredibly concerning breach of due process; the government takes away your rights before you even have a chance to prove you don't deserve them. and if you don't have those rights, how would that affect the justice system? you're essentially only an extension of your parents by the state, not an independent individual. i think that idea would almost certainly be unconstitutional
i like the way it is currently. there's no way to make the law accurate enough to only give people rights when they're ready for them or smth, so the best bet is to just automatically raise barriers at the best estimate possible. maybe a combination could be made where people could opt to try and gain their rights sooner, but that would still be expensive to manage