There's already an okay solution to supply-chain attacks against dependency managers like npm, PyPI, and Cargo: set them to only install package versions that are more than a few days old. The recent high-profile attacks were all caught and rolled back within a day, so doing this would have let you safely avoid the attacks. It really should be the default behavior. Let self-selected beta testers and security scanner companies try out the newest versions of packages for a day before you try them. Instructions: https://cooldowns.dev/
Even better, only use company vetted repos, everyone is forbidded to install directly from the Internet repos.
This naturally doesn't work outside corporations.
So you get security updates late too? Many vulnerabilities are in the wild for years before being noticed, and patched.
Once noticed, that's where the exploit explosion erupts, excited exploiters everywhere, emboldened... enticed... excessively encouraged, by your delayed updates.
IMO, the most sustainable version is either the linux distros/bsd ports/homebrew models. You don't push new libraries to the public registry, instead you write a packaging script that gets reviewed for every new changes.
Another model is Perl's CPAN where you publish source files only.
More a case for something like this from Show HN three months ago
https://github.com/artifact-keeper
An artifact manager. Only get what you approve. So you can get fast updates when needed and consistently known stable when you need it. Does need a little config override - easy work.
I had my own janky tooling for something like it. This is a good project.