The problem is that you can't require global modules, so that global module needs to have installed everything that needs, and if it needs to support multiple p

The problem is that you can't require global modules, so that global module needs to have installed everything that needs, and if it needs to support multiple projects with different requirements, that global modules needs a whole lot of modules itself in its package.json, and now that global module is unmaintainable, because of all its dependencies. That is why global modules is generally not useful and that it is better to have them installed locally.