Why A4 is better than US Letter

Canadians use that? I've never seen it in my life. I only use A4

What? I haven't watched the video (won't play) but does US have a different standard size for paper?!?!?

When someone goes out of there way to make a big statement about one thing, then says 'but don't get me started' on another I just want to punch them in the face. Clearly all you want is for someone to 'get you started'.