All these things you listed are objectively bad and a tumor and I'm glad that those that are gone, are gone for good, because the one that stayed is a menace to any programmer caring about his sanity.
I remember trying to figure out what's up with Go and left in complete disbelief when I was told that I need to install nginx on my local machine and fake a DNS entry just for go's package manager to "fetch" my local package from my local machine just so I could mess around with it how that works.
All because I couldn't care less about 3rd party services like github.
And then replies slowly devolve into arguing about irrelevant things that were solved with the existence of Linux because plan9 sucks and Linux is just a kernel which is actually used by people and therefore they actually found ways to solve problems they were most annoyed by.
All these "X is poor man's Y" are a cope. Plan9 is poor man's <insert any operating system that is supposedly inferior to Plan9> because noone uses it. I'm sure on most people the irony of this statement will be lost, so I'm gonna explain: yeah, plan9 is better on paper, too bad we live in glass world.