You lose the ability to remove unused code, but for people using this, it doesn't matter, because it is cached anyway.
The number of HTTP requests really does not matter much these days, because of HTTP2. And again for people who use this service and get a speedup from it, it doesn't matter because it is cached.
Yes that's fair, with less code you have less to parse. Parsing time is ideally a negligible amount of time, especially because it can normally happen asynchronously, but for very large libraries I could see it being an issue.
Well yes and no, this will depend on how you build and serve the dependency graph. If they did their diligence with the production build you should be able to
Optimize re-usability of common imports as well as optimizing modules to only import the bare minimum of what’s needed. Now granted as far as I can tell from a technical perspective in absolute terms you will always get the best builds tuning your builds locally, however it’s not all or nothing either
The number of HTTP requests really does not matter much these days, because of HTTP2. And again for people who use this service and get a speedup from it, it doesn't matter because it is cached.