The thing I love most about OS 1 and 2, and what I hope will be its lasting legacy in the minds of future RPG devs, is that it puts the core systems first and shows that they're allowed to be good. There have been many, many RPGs where the combat was boring, bad, half-broken, or had little interactivity besides minmaxing correctly at character creation. Instead of playing the game for the game, we were "meant" to play for the things which should be secondary window dressing- companions, romances, story, C&C, the writing, whatever. What's really impressive about OS2 is that if all of those secondary things were stripped away, and the game was nothing but a turn-based squad tactics game like nu-XCOM, OS2 would still be by far the better game, even though nu-XCOM is a AAA release that focuses on nothing but the combat.
While all CRPGs sprung from the loins of turn-based tactical strategy games, I would not say that in today's CRPGs, core systems are limited to combat mechanics. There are, at the minimum, three other aspects of gameplay:
* Character creation and progression
* Item use, management, and itemization
* Out of combat interactions
The above aspects are independent from aesthetic concerns such as art, writing, music, etc., but constitute core mechanics of a CRPG. For example, a game in which there is no character creation or progression can still be an excellent tactical combat game, but most people would not regard it as a CRPG. Just the same, even though I wouldn't consider items and itemization essential to a CRPG, its existence is more or less comprehensive. Out of combat interactions include quest design, interactive dialogue, choices and consequences, traps, puzzles, exploration, environment manipulation, and all those other building blocks one associates with CRPGs. A game with none of the above would be a very different experience and probably not a CRPG, just as the Myth games, for example, aren't.
So I wouldn't call it window dressing. Larian being an action CRPG developer will naturally favor the combat side of games; but saying that games like Path of Exile exemplify what CRPGs should be, ignores the fact that Planescape: Torment was voted the Codex's favorite game, and that game has
terrible combat. There has always been a systemfag vs. storyfag divide on the Codex and within the CRPG community, but out of combat gameplay is not necessarily tied to the aesthetics of the story, since you can fail on the aesthetics of a quest but still succeed on the gameplay design.