I think you can do copy paste in most languages. But it will be a pain to update when there are improvements / security fixes.
You got a project with 1-2 depencies? Sure. But if you need to bring in 100 different libs (because you bring in 10 libs which in turn brings in 10 libs) good luck.
> But if you need to bring in 100 different libs (because you bring in 10 libs which in turn brings in 10 libs
So don’t?
With manual deps management, everyone soon gravitates to a core set of deps. And libraries developer tends to reduce their deps needs, That’s why you see most C libraries deals with file formats, protocols, and broad concerns. Smaller algorithms can be shared with gists and blog articles.