Matewis: Batman vs Superman's fight against Doomsday
Snyder (who I think, despite missteps, is an underrated director) has great and rare talent for making fight scenes that steel retain that physical "feel" despite CG. All the fights in Man of Steel and BvS stand out from most other superhero movies for me for that reason. It all still feels like the punches have impact, and people are getting hurt and tired. I don't remember who it was, but someone once called it the "everything hurts aspect" of old school action, which is often missing now, but Snyder gets it.
Anyway, you are of course right, there have also been a lot of good, even great fights in modern cinema. I guess what I'm saying is that I don't really think of it as Conan having aged poorly, when it's still better than so many new movies (including the utter failure that was the new Conan a few years back).