So, if you don't see something you just assume that it is not there? We don't see his head either, so you think that he lost his legs, arms and head also? In my opinion that's a foundless assumption.

If I don't see that Shepard survived, then in the game, it is just implied. Which is what I said in the post you responded to.

The purpose of the breathing scene was just to indicate that he is alive. Whatever happens afterwards is up to each player, maybe in your headcanon he didn't make it and died shortly after that scene, which is fine. But the fact is that as soon as the war ends, he is alive. There is no denying that.

You can pretend that you know what the developers thought when they added that scene, but I will not do that.