I think everyone kinda agrees these days that Henry VI had some sort of severe developmental disorder. Like, he was very far down on the spectrum of functionality. I don't think he had much of the capability to be good or bad as King. You need to have that element of ability to choose at a relatively high functioning level before you can be discussed as being good or bad at something.

Worst English monarch though? Why are we avoiding the other, super large, Henry shaped hole in history? No more Henries after him, IYKWIM?

Also, there was this English King who was so bad at kinging they literally called him "The Unready" because he was so bad at it.