
They’re both true. Women do mature faster (both physically and mentally), and they get punished, blamed, sexualized, and expected to cope earlier. They’re not mutually exclusive. There’s a reason women have a higher average life expectancy, and numerous reasons for the feminist movements.
There are a handful of places. There are several villages in the world that operate on matriarchal systems, and we can also look at historical matriarchal societies. In these societies, the subtle discrimination women face is nearly, if not fully, eliminated. And women still mature faster than boys there.
It could be a combination of both. Because they physically mature faster, their pre-frontal cortex is included in that, so they mature mentally faster. But could that be evolution due to the fact that society expected them to? Because in the oldest bones we have, it's very difficult to tell the men from the women