Well said!   PM Cameron used to wipe the Commons floor with Corbyn in PMs Questions and unmask Jeremy's naive fondness for returning Britain to its 70s socialist agenda and its reputation then as the sick man of Europe suffering from "the British disease" of crippling taxes, onerous regulations, unions running the Labour government and running the economy into the ground, double digit unemployment, bankruptcies, interest and inflation rates, etc., etc.

His no show during the Brexit campaign probably did make at least a 2% voter shift that would have defeated Brexit and so his own MPs turned against him even publicly.  (Cameron observed that Corbyn was then being kicked so many times by his MPs that he reminded him of The Black Knight in Monty Python's Holy Grail.)

Corbyn would indeed be an economic and fiscal disaster for Britain and allow it to reclaim its crown now held by France as The Sick Man of Europe which it earned by importing The British Disease to France decades ago.