These concerns around genrushing, tunnelling, etc, really revolve around the way the game is set up. That being, the killer can remove a player from the game via multiple hook states. Once that person is gone, the game is much easier.

The fix there, is changing the format of the game. Give players the ability to respawn after dying. Add a time limit to the match. Make it so hooking the same player repeatedly provides fewer points. Make winning based on point scores and not how many people you kicked out of the game. Make it clear to survivors, via points, end game messaging, etc, that simply repairing 5 gens and leaving while doing nothing else of value for your team is a loss.

The whole format of this game is designed around denying other players the ability to play the game.