Pretty much everyone has given up on signing at this point, I think?

I sign all my packages (and also my release commits and tags) – the infrastructure and tools to support easy and thorough artifact verification may not exist at this point, but I’d rather see us collectively push things in that direction than give up on supply chain security altogether.

Nope. That’s never been true. It’s always been optional.

Maybe technically optional, but practically not so much – if you wanted to edit any metadata like project description, licenses, etc., you needed a pom.xml template file. The recent :pom-data in 0.9.6 is certainly a step forward.