(I've found Bintray to be the easiest.)
How many NPM repos are there? Just one, too-big-to-fail, centralized repository.
Don't ding apt/deb just because people setup their own repos rather than put all the code in the world into one bucket.
There's a lot more inconvenient things than adding the /etc/apt/sources
There are actually plenty, it's just that they're usually found on-prem at a company.