The NPM ecosystem is on the extreme end of micro-libraries, so sometimes I will just inline a library's code into my project when the indirection of using a library isn't worth it.

For every library you use, you are now trusting everyone that has publish rights to that library and all of its transitive dependencies, so libraries aren't free.

Also, sheepishly, it's so easy to publish on NPM that I'll sometimes just re-implement a library with my creature features and publish it instead of making a case for them in the existing library's issues. Awful, I know.