It definitely depends on the industry. I work in construction and honestly, I've met loads of project managers, QSs and architects who are pretty awful but still get paid really well.
That said, I'd agree with what others have said - the really senior people tend to be genuinely impressive. Not necessarily the smartest technically, but they've got that way about them, you know? They're good in a crisis, likeable, and know how to manage people, whether it's winning work or just navigating all the difficult conversations that come up.
I can usually spot early on which graduates or young people will make it to the top. They just have this ease - comfortable talking to anyone from site workers to directors, seem to know instinctively how to handle tricky situations.
I joined the industry really young without any further education and got 'lucky' because I knew when to work hard. But looking back after twenty years, I definitely had massive pretty privilege. Now I'm older, I can see why all these blokes were so keen to help out the young, attractive woman. I was completely oblivious at the time!
So yeah, there's definitely luck involved - sometimes in ways you don't even realise until much later. But the people who really make it long-term usually have that something extra beyond just being in the right place at the right time.