Keys have got to go
When your opponent has a toolbox, you can counter it by keeping that person off the gens. When your opponent has a medkit, you can chase down injured survivors so they don't get a chance to heal. When your opponent has a flashlight, you can look at walls or look up to avoid being blinded and listen for sounds if you are blinded.
But against keys, the counterplay is all but nonexistent. Keeping the gens from being repaired is largely a useless endeavor against competent opponents. Even if you bring Franklin's or tunnel the key-holder to death, their teammates can always just pick it back up. Even if you find the hatch first, it doesn't matter.
It's a terrible mechanic. It makes the Killer lose through no fault of their own. Keys need to be reworked ASAP.