In my experience, yes. It comes down to saving throws versus attack rolls. In general, it seems like it's a lot more common to hit BBEGs with attacks than it is for BBEGs to fail saving throws. That's due both to the math of attack rolls and ACs, compared to saving throws and DCs, and because there are lots and lots of ways to get advantage on attack rolls, but relatively few ways to impose disadvantage on saving throws.
And even when casters do use attack rolls, there are fewer ways to get advantage (in fact one of the ways melee gets advantage tends to give the caster disadvantage) and far fewer items that give + to hit.