Biggest issue with GitHub issues is that large open source projects can't easily signal to viewers which issues are a priority and which are dead or spam. Anytime I see a project with a bazillion issues (like Element), I worry about it's health when maybe I shouldn't because the project is actually fine and the maintainers just use some other ticketing system outside of GitHub.

Aggressive moderation to keep the # open is possible, but not ideal because it causes anxiety for issue-creators and prevents maintainers from finding out about bugs and feature reqs. Some first-class way to differentiate between backlog and todo on the repo would be my #1 request.