While I agree with you, I'd like to point out there are interesting exceptions: software components that can never be "complete".
Such components require permanent maintenance workforce, and you might not want to dedicate resources for this.
Such as:
- API abstraction layers (like SDL, Allegro, SFML, etc.): you want to support new operating systems / new APIs by default. And most of the time, you don't want to spent time learning about the specifics of X11 window creation or Win32 events, as this would be throw-away knowledge anyway.
- hardware abstraction layers: you want to support new hardware by default, this is why we use operating systems and drivers.
- Format/protocols abstraction layers: if your game engine only uses JPEG files directly coming from your in-house asset pipeline, it's perfectly fine to develop in-house loaders (from scratch or from stb_image). But if your picture processing command-line tool aims to support every file format (especially, the ones that don't exist yet), then you should rather go with an updeatable third-party library, which will allow you to get all new formats by default.
- all kind of optimizers, including compilers, code JIT-ters, audio/video encoders, etc. More generally, all code that uses some heuristic so try to solve a problem that's not completely solved/solvable. You might be ready to accept the performance of a specific version of, for example, libjit. But you might instead consider that in your case, not having state-of-the-art JIT performance might be detrimental to your business, in this case you want to get the performance enhancements by default.
Such as:
- API abstraction layers (like SDL, Allegro, SFML, etc.): you want to support new operating systems / new APIs by default. And most of the time, you don't want to spent time learning about the specifics of X11 window creation or Win32 events, as this would be throw-away knowledge anyway.
- hardware abstraction layers: you want to support new hardware by default, this is why we use operating systems and drivers.
- Format/protocols abstraction layers: if your game engine only uses JPEG files directly coming from your in-house asset pipeline, it's perfectly fine to develop in-house loaders (from scratch or from stb_image). But if your picture processing command-line tool aims to support every file format (especially, the ones that don't exist yet), then you should rather go with an updeatable third-party library, which will allow you to get all new formats by default.
- all kind of optimizers, including compilers, code JIT-ters, audio/video encoders, etc. More generally, all code that uses some heuristic so try to solve a problem that's not completely solved/solvable. You might be ready to accept the performance of a specific version of, for example, libjit. But you might instead consider that in your case, not having state-of-the-art JIT performance might be detrimental to your business, in this case you want to get the performance enhancements by default.