If you wanted a definitive answer than this is not the film for you, sorry.
I'm just sharing thoughts that came to me after watching the film; I'm not saying anyone has to agree. Strangely enough, you seem to be telling us that there's only one answer (no answer) and we should go away if we don't agree with you. You see your open thought as the absolute definitive; I make no such claim for my thought.
My post wasn't in reply to yours. What I'm saying is that the film offers no definitive ending and people can argue this all the want but they'll always be wrong (or, not fully right) because we don't see the top fall. They can argue it was falling or it wasn't but it doesn't matter. It ended before we could see the results. Of course people can have an opinion on whether it was a dream or not but it's not 100% for sure.
My opinion is that worrying if it was a dream or not is beyond the point.