Far easier to use something that 1000's of others are using as well. Far more likely for edge case bugs to surface.
That said, I have to agree that it can be painful trying to get one of those edge case bugs resolved if you are the only one being impacted. In this case I may be worth just implementing your own functionality and swallowing the future support. But I think it's got to be a backup plan, not your first response.
The real problem is that most developers don't have the experience or knowledge to go beyond accepting the "use xyz library" suggestion on Stack Overflow on face value, not having the ability to review xyz library for suitability. We end up with lots of code that is just collections of dependencies where only a very small % of functionality is used and no resources are put into ensuring that using the dependency is not introducing more problems than they solve.