Generally, other package managers aren't great either. Notably, crates.io / cargo has some of the same issues as NPM and the verbiage of their excuses for not fixing these problems is oddly similar.

Something fascinating about the design and architecture of programming languages and their surrounding ecosystems is the enormous leverage that they provide to the "core team":

For every 1 core language developer[1]...

... there may be 1,000 popular package developers...

... for which there may be 1,000,000 developers writing software...

... for over 1,000,000,000 users.

This means that for every corner that is cut at the top of that pyramid, the harms are massively magnified at the lower tiers. A security vulnerability in a "top one thousand" package like log4j can cause billions of dollars in economic damage, man-centuries of remediation effort, etc.

However, bizarrely, the funding at the top two levels is essentially a pittance! Most such projects are charities, begging for spare change with hat in hand on a street corner. Some of the most used libraries are often volunteer efforts, despite powering global e-commerce! cough-OpenSSL-cough.

The result is that the people most empowered to fix the issues are the least funded to do so.

This is why NPM, Crates.io, etc... flatly refuse to do even the most basic security checks like adding namespaces and verifying the identity of major publishers like Google, Microsoft, and the like.

That's a non-zero amount of effort, and no matter how trivial to implement technically or how cheap to police, it would likely blow their tiny budget of unreliable donations.

The exceptions to this rule are package managers with robust financial backing, such as NuGet, which gets reliable funding from Microsoft and supports their internal (for-profit!) workflows almost as much as it does external "free" users.

"Free and open" is wonderful and all, but you get what you pay for.

[1] Most of us can name them off the top of our heads: Guido van Rossum, Larry Wall, Kerningham & Richie, etc.