The problem that comes with being a premier city in a country, is that there is no planning done.
Right now, everyone descends on the CBD. All directions inbound. And the Bridge is the main thoroughfare outward. One Bridge. That's the problem.
In my opinion, right now, the CBD should be in the area that Strathfield is in. Central in the middle of the greater metro area, and a hub with public transport, and multiple ways in and out.
That's why the Government is trying to make Parramatta the second CBD, but really, one would suffice.
Something that wasn't thought through properly was just how much the city would expand.