> But how is it any different from keeping them open?

If all open issues are actionable items, that makes expected workload a lot easier to handle.

If most open issues are actually in "needs triage / needs review" state, you lose the signal from the noise.

The issue tracker for a project exists primarily as a tool for maintainers, not for outsiders. Yes, the maintainers could change their workflow to create a new view that only shows triaged tickets.

Or, they could ensure the default 'open' view serves their needs.