The most important skill for a software engineer IMO is debugging. Writing code is easy. Willingness and ability to debug through layers of abstraction, through code you didn't write, perhaps deep into other areas of the stack (libraries, frameworks, the server, the browser engine, etc.) can prevent you from ever being "blocked".
This is a skill I see lacking in a majority of developers these days. Too many people just stop as soon as they hit code they didn't write. They just report it to another team, file a GitHub issue, etc. And then complain when it isn't addressed for them immediately.
Your dependencies are your code. You are responsible for them. You can't rely on other people to fix problems you run into all the time. Understand your stack deeply. Learn to debug. It'll help you immensely.