I actually think that the Tories are pretty awful, as well. For many years now, they've maintained the fiction that they are a party of the right. They're not. They're a glee club for self-interested and the privileged. On occasion they have managed to convince the impressionable that they represent the interests of all.
Johnson just happens to be the most recent and egregious example of their leaders. He stands out as probably the most dishonest and incompetent, who has surrounded himself with the similarly hopeless.
I think that there has definitely been a noticeable decline, but I hold out for a return to the better days.