npm does support "scoped packages"[1], since 2015. More projects are starting to use them, e.g. Angular publishes packages like @angular/core, @angular/forms, etc.
It's not that great unless it's required. For example, the bare "sqlite3" package name will always sound official/canonical next to "@JoshuaWise/sqlite3" and people will forever accidentally install it even though they want a scope. Just like how users type in domain.com when they really wanted domain.org.
[1] https://docs.npmjs.com/misc/scope