Inserting an "intelligent designer" guarantees we will never find the real answer.
Absolute hogwash. Since intelligent designer does not have to mean supernatural, then if another biological life form was the intelligent designer then that gives a good chance of the process eventually being discovered and able to replicate. If this never happens, then more than likely a supernatural designer, other dimension, or our universe is a simulation of some sort. Random or biological design will be able to be replicated at some point.