While I empathize with your team regarding their apparent workload, that's only because they (probably) don't control hiring. GitHub isn't a struggling startup; it's not a non-profit; it's a mature, sizeable organization whose owner has over a trillion dollars in assets. If the team is too small to do a job, it's not because you lack personnel, it's GitHub's choice not to do it. You're GitHub, owned by Microsoft; GitHub doesn't care about these issues enough to staff them.
EDIT: Removed something provocative.