Transpilation is the number one reason I've seen that makes maintenance of older projects hard. The fact that JS didn't standardize on a module syntax until far too late means that we're forced into a transpilation cycle to build bigger projects. I can call that a mistake without denying it's reality.

If you want to build a web application, at some point, until we have true web assembly, you will have to use javascript, which does make a lot of the arguments here moot, regardless of the size of the project.