seriously mate, is that what you believe to be right..... oh dear.
you couldn't be more wrong if you tried.
i'm not talking about line issues/ip profiles/sync. of course if you have problems with these things, switching isps is not going to fix it. this is indeed a problem between your house and bt (wholesale) equipment at the exchange.
but for people with solid lines/sync rates but are being throttled during peak times, their problems really do disappear overnight when switching isps. you don't have to take my word for it. look around. you'll see it everywhere.