Sorry for the foul language but I had one too many of this.
Having worked with a good few Open Source tooling/libraries/frameworks etc and with a lot of similar internal ones I have come to the conclusion that almost invariably the quality of the later is far below the quality of the former. Being documentation, ergonomics, bugs, you name it.
Open source alternatives are much better than proprietary closed source ones. Mind you that I'm not talking about code quality, I'm talking about mere usability and dev experience.
This is consistent across quite a few medium, large and very large companies (enterprises) I've been. Worst case (and quite common) is when a company "builds" upon OS (e.g. a framework based on Flask). The end result is a painful to work with half-baked mess.
What I don't get though is that OS is built (in many cases) by hobbyists for free. The internal messes are always being built by people on a steady payroll. I just don't get it...