Secondary shower thought, an image of Captain Caveman should be the image representing humans on the Wikipedia page.
Tertiary shower thought, we probably started wearing clothes because our own hair used to be our clothes, and we wanted to replace the hair we cut off when we started grooming.
Although peoples hair has a max length that is dependent on the person and the situation. That is why people growing out hair need to have dead ends cut off so that it will grow more. I would not be surprised if like the zz top guys had to so something similar to get that length.
Cutting dead ends doesn’t promote growth, but it prevents the hair from getting shorter. Split ends (being finer) are weaker and more liable to break, tangle, get caught in a brush, etc. Cutting them off stops the split from getting longer.