Which you do not describe, but set that aside: A post that honestly said "we do not like PGP, but here is our alternate plan" would be great. On an actual better solution, I don't think anyone has proposed a good one. Here is the closest I've seen from PyPi (or at least linked from this post as describing their thinking), from 10 years ago:
"Everything is Terrible So What Do We Do?
Bluntly put, I don’t know for sure. This isn’t an already solved problem nor is it an easy to solve one."
What I'll say on PGP is the perfect is the enemy of the good. It's not a tech anyone has much fun using, but in a group setting, used regularly, I have found it can fade into the background at least. I don't want to go any further down the "is PGP good or bad" rabbit hole than that.
But if you have a better solution for package security, please do describe it here.
The current documented plans revolve around TUF (https://peps.python.org/pep-0458/, https://peps.python.org/pep-0480/). Those links have probably bit rotted a bit by now, progress has been slow on implementing them for a number of reasons (mostly OSS reasons, volunteers etc).
There's also a general consensus (not documented) that sigstore will play some kind of role here. Possibly in-toto as well?
In the 10 years since my post that you referenced, we've laid some decent plans I believe, and have just slowly been working on them, to the extent that we've been able to given our own time constraints.
"Everything is Terrible So What Do We Do?
Bluntly put, I don’t know for sure. This isn’t an already solved problem nor is it an easy to solve one."
https://caremad.io/posts/2013/07/packaging-signing-not-holy-...
What I'll say on PGP is the perfect is the enemy of the good. It's not a tech anyone has much fun using, but in a group setting, used regularly, I have found it can fade into the background at least. I don't want to go any further down the "is PGP good or bad" rabbit hole than that.
But if you have a better solution for package security, please do describe it here.