In software engineering or tech, more than any other field, nothing trumps raw skill and knowledge. That’s the best thing about building a career in this industry. Jobs here are given through meritocracy. There’s no chance for nepotism IF you’re joining a proper team/organization.
Don’t let anything let you believe otherwise. If you’re not where you want to be career-wise, it’s most likely a skill issue. Not a luck issue. Not because you don’t have any inside connections.
And fortunately, that’s the good news! You can work day in, day out and pump out code to build that skill eventually. You don’t really have to navigate intricate human interaction and politics to climb the corporate ladder. The impact these things have on a developer’s career is much less than all other careers I believe.