Agree. In two absolutely futile cases I no longer engage, at all, ever.
In the present case, however, a short, simple statement was made. It should have been very easy for that statement to be backed up and validated. But it wasn’t; the back-up evidence has not been provided and probably never will be.
It’s typically this way with a particular kind of belief system. Statements are routinely made that cannot be substantiated. That’s just the way it is, because the system itself rests predominantly on belief, as opposed to resting on facts, logic and evidence.
There's a difference between 'will not be substantiated in this current discussion' vs cannot be.
Yet again we can observe a real difficulty to incapacity to discriminate, discern distinctions between different classes of reality.