It's worth noting that node_modules is for project dependencies and most of it won't be included in the final assets. Many projects make use of build tools, command line utilities, testing suites and other libraries in development which don't get deployed. Even for actual app dependencies, many packages include source code, type definitions and multiple choices of builds which inflate the size of the node_modules folder but don't get used in production. So hundreds of megabytes of dependencies can easily be used to make something only a few megabytes in size.
Your point still stands of course!