Why oh why.
It seems Larian really don't understand why NPCs and especially enemies need to be limited in their toolkit, just like they are in the Pen&Paper game (basically simple Monster stat blocks with a few particular actions).
Giving opponents exactly the same abilities as a player character of approximate class and level spells utter disaster. D&D rules are NOT designed to work this way, not to mention it adds unnecessary complexity to enemy AI.
Interesting take...
It would seem that we've had VERY different tabletop experiences. Granted... I've only been consistently playing tabletop RPGs on a weekly basis for 35 years now, so I may not have the experience necessary to weigh in on this... but myself (when I was DM) and the DMs that I've played under have always built NPCs exactly the same as the player characters were built and given them exactly the same stats and abilities as player characters would have received. The only real difference is that hostile NPCs have usually been anywhere from 1-5 levels higher than the party.