I'm not arguing that one should write things from scratch. I think I may have poorly articulated my position, but that you and I actually share the same opinion here.

I don't think you should reinvent the wheel unless for some reason all available wheels are insufficient for your case. But knowing this requires that you have some understanding of how wheels work, how to compare them, and how to hew your own out of raw materials if the need arises.

I would say JS is partially a wild west due to title inflation and the relative numbers of lesser experienced developers in the space relative to, say, your pool of Erlang engineers.