In my opinion, and oversimplified on a 1-10 scale, savage is a 7 while ARR-ShB dungeons are a 3. Some of the newer dungeons are a 4, and that is significant. They are harder.

This game used to have two big problems. One, casual content was too easy and mindless for anyone who was merely average at the game. And two, the gap between the normal dungeons and raids, and savage, was so wide that the former doesn't prepare you for the latter.

This game still has both problems. But I respect the developers for trying. Their attitude of "this is the fifth expansion, please get better at reading the orange" was a good take.

You'll improve. Also if you think something has split-second reaction time, then you missed a tell. Some orange hurtboxes only exist to show you where the damage was so you can learn it and avoid it next time. And some exist for only a second so you can make a small adjustment if you're close. You're supposed to have mostly dodged the attack before the orange appears in that case too.