What is the point of combat?

Currently finishing up chapter 2, so correct me if things change down the line, but what is the point of combat? Outside of the fact that combat skills do not transfer between chapters/zones, why would you want to push combat skills further than what is required to finish up the chapter? There are no real incentives to train combat skills outside of killing harder mobs that might loot better gear (not usable in other episodes anyway). There are no other skills that rely on combat, and there are no "bosses" or dungeons or mechanics that would present a long-term incentive. I know that could be said of other professions (like cooking), but shouldn't combat be the profession with the most care put into it?

Also, better gear and leveling up combat do not seem to satisfyingly increase your resilience and damage.
And what is the point of classes in the end? I have not encountered "special skills" yet, is it just an elemental trinity à la pokemon?