I have seen culture changes in what are considered appropriate ages. When I was young the voting age was 21 - as it should be - as was the drinking age. The driving age of 16 is left over from the era of farm vehicles and having to get to a job. Rolling hotel rooms wasn't the original plan, and they still aren't good drivers. 18 would be better. People married younger. I knew people who married right out of high school, but that is rarer now. Relatedly, among those not going to college there were two sharp divisions. You either moved out of the house and struck on your own fairly soon after HS graduation, or you lived with your parents until you married. If the latter, you were expected to be contributing financially to the household. This was not always seen as "paying rent," but as "being an adult in the household." I had a few friends who turned over their paychecks to their mothers every Thursday until about a year before they married, at which point they were allowed to save for that new life. Yet there were many who got their own room or apartment at 19 or so, expected by their families to be self-supporting.
There are now stories of parents being reported to the police or DCYF for letting their children go to the park unsupervised. I have seen more than one where the child in question was as old as 11. Not only in my era, but into my children's era, 12-year-olds, especially girls, would be hired to babysit younger children. 11 and 12 are very close numbers. I walked through the city to the library or the Y when I was 6, and would take off on my bike with friends on a Saturday morning for hours when I was 9. No one thought this unusual. I don't know that it was better. I doubt I learned much about good judgment from it. Some resourcefulness, perhaps. Yet also the downside of being young with a broken bicycle miles from home was also the message of how alone and unprotected one is in the world. Get used to it. Not sure that really is a positive. But point being, it was universally believed that a group of ten-year-olds was old enough to pack lunches and go exploring, so long as certain forbidden areas were avoided. Be back by dinner.
There was a case in some southern state in the 1980's that pro-choice activists used for fundraising, when there were attempts to mandate parental consent for abortion for girls under 18 (or 16?). While the law in that state made provision for a girl to go before a judge for permission if her parents were abusive or otherwise dangerous to her, in one particular case a 14-year-old with horrible parents had gone before a judge but was denied permission. This was part of the true-believer, foxhole friend, Toxoplasma of Rage insistence that there would be no compromise, none, though there was enormous public support for the idea at the time. Okay, a lot happens in maturity between 11 and 14, but a lot of that is physical and more appearance than emotional. 14 isn't that far from 11, to be able to say "This one can't go to the park alone, but in three years she can consent to sexual relations in many European countries (and don't even ask about Africa), and should be able to independently consent to an abortion.
Related in a vague way. Conservatives sometimes make the accusation that some women seek abortions because they don't want the "inconvenience" of a child because of their careers, or just don't want to be responsible for adult actions. This may be so. In fact, I am sure that it is so in some cases. But I think there is an additional reason that is seldom mentioned. I confess this interpretation may be terribly dated at this point. When I was in dating ages, girls/women made efforts to hide the fact that they were sexually active - from their parents, even from their friends, and they were absolutely sure it was nobody's damn business in the general public. Being visibly pregnant made that part of her private life public. I doubt that is a huge motivator among 28-year-olds these days. But I'll bet it's still an issue for those under 20. More importantly from a political POV, 60-year-old women remember when it was important to them at age 17 that it was nobody's business what they were up to, and how necessary it seemed, for their friends and themselves, to keep that last escape hatch open. The complaint that women are being forced to have children, while logically ridiculous despite Handmaid's Tale and just like rape rhetoric, is more likely to have its root in those early days of secrecy being all. Visible pregnancy is forcing a girl/woman to out herself as sexually active.
I don't discount the other motives. I just add that one in.