They've just never been easy to deal with
The biggest problem for me is the unenthusiastic replies - sometimes, none, which is just a big turn-off.
Are you looking for this? Most GNU projects are hosted on Savannah. Yes, it is very ancient and inconvenient.
That webpage is pretty terrible. Why isn't Forgejo or GitLab being used? Is there anything wrong with it? I also like how I am not forced to share my personal email in those webapps.
There are at least two reasons: savannah is used since many years before gitlab has appeared and it is usable without JS.
I don't trust GitLab.
Updating Guix packages is super simple (as described in the manual). Check out the sources, create a patch, email said patch and wait.
For other (GNU) projects this may be a lot harder
GNU's Not Unix
GNU related news and discussion.