> How about storing issues and PRs in the actual git repository?
Access to the git repository is regulated; issues and PRs aren’t. Anybody can fill an issue/PR on your repo, but only you (and your team) can modify the repo. You’d need to also store all the comments on all issues and PRs, even closed/rejected ones. In some repositories, that’d be huge.
> And the amount of actual data needed to store issues is peanuts anyway.
It’s not. Take something like github.com/Homebrew/homebrew-core. There are 15k closed PRs there. There have been 20 new ones today. It’s not rare to have 10-20 comments per PRs; some of them even go over 200. Add CI status, actual PR contents (git patches), comments reactions, edits, labels, milestones, assignees, reviews, projects.
IMHO having a tool to fetch issues locally is a good idea; storing them in the repo is not.
Access to the git repository is regulated; issues and PRs aren’t. Anybody can fill an issue/PR on your repo, but only you (and your team) can modify the repo. You’d need to also store all the comments on all issues and PRs, even closed/rejected ones. In some repositories, that’d be huge.