Insulting cavities well is immensely labor intensive and unfortunately is still required in homes with exterior insulation so you're kind of getting the worst of both worlds. Exterior insulation is an absolute breeze in comparison though, there are tons of product on the market that integrate the sheathing and insulation into a single unit so it installs just like any other exterior sheathing would.

Exterior typically requires sheathing and insulation is attached to that sheathing. Extra work is required to tape up the seams though it eliminates the plastic house wrap required in most areas in the US which is attached with staples or a nail gun.