I try to make this point when the subject comes up, but IMHO this is a lipstick-on-a-pig solution. The problem with npm security isn't stability or attestation, it's the impossibility of auditing all that garbage.
The software is too fine-grained. Too many (way too many) packages from small projects or obscure single authors doing way too many things that are being picked up for one trivial feature. That's just never going to work. If you don't know who's writing your software the answer will always end up being "Your Enemies" at some point.
And the solution is to stop the madness. Conglomerate the development. No more tiny things. Use big packages[1] from projects with recognized governance. Audit their releases and inclusion in the repository from a separate project with its own validation and testing. No more letting the bad guys push a button to publish.
Which is to say: this needs to be Debian. Or some other Linux distro. But really the best thing is for the JS community (PyPI and Cargo are dancing on the edge of madness too) to abandon its mistake and move everything into a bunch of Debian packages. Won't happen, but it's the solution nonetheless.
[1] c.f. the stuff done under the Apache banner, or C++ Boost, etc...
The fact is that being Debian is boring, and JS (python/rust/...) is *cool*.
Give it a few more decades, hopefully it'll be boring by then, the same way, say, making a house is boring.
Agreed on the "this needs to be Debian" part. If some of the most popular JS packages were available through the system package manager as normal *.deb packages, I think people would be more likely to build on top of stable versions/releases.
Stability (in the "it doesn't change" sense) is underrated.