[avereveard]

sure these framework may do just in time transpilation and compression, that doesn't mean you don't have a build step.

copying the code to the server becomes the build step.

except now you have no chance to lint the code before shipping it

"but I can lint it on my machine"

good, then you have a build system, and you may as well just get the optimized stuff on the server, since server startup time depends on your code size at some point or another, and you pay for that.