Ummm... yes.

How software is maintained by an OS is different from how software is maintained by 3rd party developers.

- Python has long strongly recommended virtual environments.

Yes, if you are developing a private application. But if that application gets adopted by the OS then you can expect all it's dependencies to be sent to a place like `/usr/lib/python3/dist-packages`.

> Not to talk about JavaScript which of course manage things per project by default.

I didn't bring it up because it's one I'm not familiar with. I expect OS maintainers will do similar things with it that they do with python but I'm not 100% on that.

> I don't remember what was the state of things in .NET Framework, but in modern .NET NuGet packages are distributed as DLLs with your app.

And if your .net application ends up installed as an OS package you can expect those dlls to be stored in /usr/lib.

If you are doing C/C++, as a 3rd party app, you aren't putting the .so files or the .dll files in /usr/lib or C:\Windows\System32. You are storing them in the same directory as your application. But if the OS decides to distribute your app, you can expect your .so files to get put into /usr/lib and even System32 (very very rare for MS to do that, but it does happen when, for example, we are talking about drivers).

Edit: Re: node. Here's the debian guidelines for how dependencies ultimately get shredded and distributed. https://wiki.debian.org/Javascript/Nodejs/Manual?pow_referer...