Then why drop jQuery? "It needn't be part of the default stack any more" doesn't hold up as a reason any more because it's not about whether something's needed

Then why drop jQuery? "It needn't be part of the default stack any more" doesn't hold up as a reason any more because it's not about whether something's needed or not but whether it's useful. Most sites require jQuery, most developers are happy using it, why put the effort into getting rid of it?