Again..But that is trivial to do. If not enough creatures are targeting Fortitude (Constitution), then the published dungeon crawl adds a few rooms that do target Fortitude.
Only works if both DM, Player , and Designers agree to the base assumption.
Because I could make a Death Strength Save spell that pulls the target 50 feet under ground.
It's why AC Dextery vs HP Constitution works but Banish Charisma doesn't.