The royal succession is controlled by statute, making the matter of succession one of life and death. It has nothing to do with Cleopatra, but its to do with when one is born to a monarch, regardless of character , capacity or body politic.
Charles would indeed ruin the monarchy. The knives come out. But then he does have a bad heart.
Well, watch the wheels turn ‘round.
The succession is ruled by birth; and nobody is going to do what you suggest.
(I guess you think that the royals killed Diana, too...)