What's the business model, I wonder? The reason npm registry didn't evolve much is that it is expensive to give away cloud services and eventually got sold to Microsoft, who presumably assessed that adding features wouldn't drive much extra revenue. How many people publish private packages to npmjs.com how much does it cost to host and serve the ever growing collection, especially as they're pretty lenient about people serving large binaries from it?

The Java world got burned by this a few years ago when JFrog shut down Bintray, which had been the second largest open source package repository after Maven Central. A ton of stuff had to be republished, a ton of build configs updated. Now Maven Central is hopefully Too Big To Fail and Sonatype is a sustainable independent business, partly due to the widespread practice of companies buying its Nexus product to mirror Central internally, something I haven't seen so much of in the JS space, and partly because the Java ecosystem doesn't tend to host giant binaries off it. But still.

Gotta admit, I'd like to see a more decentralized approach become popular here. There's no specific reason packages always have to be hosted in one or two central registries.