As much as I like to contribute to open-source, the reality is I have budgets and deadlines to meet.
Most libraries out there will do a LOT of things I couldn't care less about, making them harder to integrate and debug and reason about, on top of bloating your executable.
I do agree there are a lot of amazing libraries out there and we do use a lot of them. But that's after analyzing them and figuring out they solve our problems and actually will save us time. For the vast majority of libraries we look at, its usually faster and better to roll our own.