True. Linux and other projects that have a mail workflow. But there are contexts where developers chose a differently, such as using a forge.
Whatever the reasons, this is where we are now. There are two paths forward: a) convince people using forges to switch to a mail based workflow, b) federate forges. The first is what SourceHut and others do. Gitea chose the second option and implement federation.
It’s not a competition, there is value in both approaches.