[tatef]

In my opinion, Trex is actually working against what npm introduced to Node. Though I don't exactly know what "main problem" you're referring to, I can say that:

1) Trex is supporting multiple module registries, not just one. (Thus not necessarily centralized) 2) Trex is not associated with one entity in particular. This means that they have no company dedicated to hosting modules in house (another reason that they aren't centralized) 3) Node's package.json included many other things than just imports. Using Trex is completely optional, and if you do use it, an import map does not hinder one's development workflow. In my opinion, it makes dependencies easier to manage.