The provenance gap is real, but most developers just rely on their scanning tools to block bad packages - which normally relies on a CVE - and malicious packages don't get CVE numbers.

GHSA and OSV have started tracking them as advisories - but the infrastructure to actually find these in a given system is still lacking. Most tools are still just checking NVD/CVE.

So the attestation signal was there, the malware flag comes later - normally after the malicious version is already pulled - and nothing in the average developer's toolchain is telling them that they got hit.