Which is why they cleverly moved the central story of a software change from the commit to the PR. Commits migrate automatically with the repo. But migrating PR descriptions and comments takes engineering effort.
Where would you put comments then? Sure, there’s always mailing lists, but even so, someone still has to host Mailman.
I do think GitHub has positively contributed to the software industry and open source. It’s been enshittified for sure, but it has had a golden era.
Rhetorically, why can't folks add the feature of PRs to Git? Git is fundamentally just a graph manipulation engine and data structure. It would just be another object type, in a layer which sits above the normal commit graph. Obviously there is no "just make X" in software, but this feels reasonably achievable, and would have tremendous benefit for the cost.