[mironathetin]

"You're solving problems. If you do work to solve those problems, fine, but having more "output" doesn't make you go from a 1x to a 30x engineer."

No, you're not only solving problems. Especially with a complex stack of software, you also try to stay in control. This could mean, a library or a third party software adds a clean, encapsulated and controllable part to your software.

This can also mean, you add a library, it works, first, but then you discover bugs and missing functionality. What then? Raise tickets on the third party software and wait and swear? Write code around the bugs, until they are solved (a 100% loss of developer time). Add required functionality to the library, which makes you depend on the installed VERSION and each update requires more time invested.

It is a decision, how important the job is. Developing key functionality in house, not to re-invent the wheel, but to stay in complete control, can be a time saving option, even if it takes weeks of initial investment that could be saved with a third party solution.

The discussion, who is more productive, becomes then really a side problem.