How does that make the cash rate irrelevant?
If falls in the cash rate have no effect whatever on the rate Joe Public pays on his mortgage or any other loans he takes out, I would say that makes the cash rate "irrelevant", but I guess that's just my opinion. "Any economic unit can emit money. The serious problem is to get it accepted" Hyman Minsky
This is reminiscent of the way Peak Oil means that OPEC can no longer lower prices by raising production, but they can still raise prices by withdrawing production.
Peak Credit? When the capital development of a country becomes a by-product of the activities of a casino, the job is likely to be ill-done. — John M. Keynes
On that logic, you are effectively dividing into two possible alternatives: