No matter what armor is used, it wouldn't be able to survive the force of a direct hit from a dragon. That's be like running over a can of meat with a truck. No matter what they do, the person is going to be squished to a paste. And yet the game, both gameplay and lore, treats it as something someone can get up from. So where is the realism in that? Really with that in mind, such material already exists if people can survive forces like that. So then where is the problem?
I'm sorry, but why - out of a sudden - you're talking about Thedas as if it was entirely realistic, even though only a comment earlier you were talking about writers just inventing a force-absorbing material out of the blue to alleviate the inherent design flaw of boobplates?
THE PROBLEM that you seem to ignore is it that Thedas has its own set of established rules, that blends realistic physics with a limited amount of magical/supernatural elements. Magical barriers, wards and special materials help to dampen the impact from the dragon, for example, but they don't lift enough of laws of physics to also save the wearer of ridiculous armor, ESPECIALLY if - at the same time - they have to protect themselves from impact of a dragon.
It's really easy to understand, or at least - it should be.
In your example, you argued that someone couldn't survive the force of an arrow to the chest if wearing boobplate armor but could survive a "direct hit from a dragon the size of a house" if wearing regular armor. If the former isn't realistic, the latter definitely isn't realistic.
That is actually Iron Bull's example, taken directly from the game.
Also - you realize that a focused strike with an arrow has a STRONGER, albeit more localized, impact on the area it hits? In fact, ARROWS (or more specifically: longbows they were fired from) were the reason why medieval armies eventually got rid of ridiculously overweight heavy plates (read who and why won battle of Crécy).