I mean hair loss treatment is a multi billion dollar industry so idk if it is that unknown, the money gotta come from somewhere.
I think the shave it bro route is just so ingrained and forced in society that people just don't bother looking into actual treatments and may assume the ones that do exist are just scams or too expensive or too risky because of side effects and just go into the shave it route. I tried to read about hair transplants in my country and literally 90-95 % of the comments where some variation of the boring *** "just shave it bro" "Jason Statham bro" "bald is a sign of high T and manliness" bla bla bla.
And in general I don't think most people care extremely much about hair loss, most people just have slow hair loss over decades, so there isn't as much of an "urgency" to treat it (if my hair loss was super slow over multiple decades I'm not sure I'd care as much as I do now). For people with fast aggressive hair loss there can be more of that urgency, but then the above applies, and people in general have a tendency to bury their head in the sand and just ignore problems, and then whaddya know they're bald. Life of course isn't over when bald, but they will still have lost a big part of their identity and ended up looking worse than before due to baldness.
I do think treatment will become more popular and widely-known in the future, I've seen youtubers in recent times sponsor stuff like keeps and such.