The cost of the alternative : doing it yourself, is also often underestimated.

"It's just a simple JSON parser, we can write our own" is a dismissal that can sink you down a rabbit hole of bugs and future technical debt.

The most important thing about using a third party library is that its easy to replace with another one if it doesn't work out.

Don't let third party data types or dependencies leak out of the module where you use them, for example via an API, and things go a lot smoother