[edem]

It is not that easy to hop in and fix stuff especially if you are not versed in that technology or if the code is crap. There are a lot of very good libraries which are quite easy to maintain and a lot of horrible monstrosities which you'd rather not touch.

I also think that there are a lot of libraries which are experiments and don't try to fill the gap. A lot of folks write something to learn a tech and put it on GitHub to show off. This is a win-win and I don't have any problems with that.

In case of Java there is a hard barrier: putting things on Maven Central. If you pull something from there you can be sure that the author went through the hoops to be able to publish stuff there and he/she is serious about his stuff.

With Javascript the barrier is so low that npm/yarn is flooded with crap.