Combat Episodes Are My Favourite Ones And Are Integral To The Medium.
Idk if anybody can relate to this but occasionally I see people upset about having to watch combat episodes in D20 seasons. And it really annoys me. Because I much prefer the seasons with battle episodes than without. They are a very useful thing for the story to build towards, where pivotal moments in the story are very likely to happen. Also I find the strategy infinitely interesting, e.g. when Emily uses a spell to destroy Brennan, or Ally comes up with an insane, but very in character/lore way to break a battle.
Also there are far more seasons with other systems like kids on bikes, or battle light 5e seasons, like the ones Aabria runs. Which definitely work very well, but don't lend themselves to all types of stories DMs want to tell.
Basically I think D20 has some of the most exciting combat design I've ever seen in 5e, and elaborate combat sets that you're not likely to see anything similar to anywhere else. So yes, they are important to the story, they give variety to the episode structure, and often the first battle is the moment I truly get invested in the story, as it sets up the stakes incredibly effectivly.