I always get confused by the term inventing .... building a wheel != reinventing it. If you know exactly what you need and you got the time why not write it? npm does not guarantee LTS for packages.
The question is more complex than just two factors it has other concerns to factor in as well:
But often devs don't factor in those accounts, but use a more generic phrase
Whatever that means. My idea is more along the lines of:

so I can focus on my task instead of a subproblem that someone else maybe already solved. But how this is achieved or if I can trust the others to deliver what I want and in the way I need it are different questions.