whats with aoe hit markers

[ProxyTooMuch]

I don't know why no one has answered his question yet. It's a pretty simple answer.

Some abilities have shorter cast times and you will have less time to dodge them.

Landslide, for example, has a fairly long cast time and whereas Weight of the Lands has a shorter cast time. So you will see people pretty much never getting hit by Landslide but will occasionally get hit by Weight.

Since you're comparing the dragon breath to open world abilities, that's the difference. Pretty much all open world enemies have ridiculously long cast times and you'll be out of the aoe circles ages before they finish the cast.