It the Big Bang theory has merit why could the Universe be smaller so we could see the edge of the Universe ?

Answer 1

I guess it could be long ago before today's scientific knowledge had been developed, at least we might have thought so as primitive people.

You lost me when you gave the Big Bang Theory merit though(or proffered it as a working set) The universe cannot be understood by it's ends (or by dimension) because you cannot create the edge except with illumination for vision and our own discovery. Therefore, the assumption is faulty and does indeed lack merit. Cheers. @8-) Good Question!