You can call it as luck/fate/destiny or whatever that you like, yet you can work your way up if you're really persistance.

I have seen ppl who have no fancy degree, from non-ivy league, breaking into the ib, with lots of efforts put into the networking. You can do the same by taking initiative to speak with 50 or 100 ppl in the industry. All you need is just 1, just 1 soul out of these 50 or 100 who is willing to give you chance.