Libraries and when to use them is a complicated decision.
On the one hand you have well tested, almost standard things (In my field, FFTW for example falls into this category, or something like libsndfile), which are generally acknowledged to just work, and have been standard things for the last 20 years that everyone uses.
On the other hand you have random stuff from github, with no test suite and only about 1 maintainer, generally why bother?
The acid test for me is firstly does the library fit into my architecture (Sometimes, if you know you want to use a given library you end up designing around that), and do I think I am going to wind up debugging someone elses library code?
A good proxy for the second question is "Is there an automated test suite and what is the documentation like?".
A little debugging is not a major problem, but at that point the library code starts to count against my own code size from a maintenance perspective (More so if my fixes cannot be pushed to upstream for some reason).
I would also differentiate between libraries and frameworks, for all that the distinction is sometimes not that clear cut, frameworks in my (small core, DSP heavy) world tend to be a pain in the arse, especially if you are trying to merge more then one or do something slightly outside the lines, libraries are sometimes useful. I am aware that this is seen very differently in the web dev scene.
End of the day it is a decision that comes down to taste and experience, and even the experienced sometimes pick poorly, still at least with a library, you can always tear it out and write your own implementation if it gets too annoying.