Oh yes it is.
But, like many things, it can't be seen for what it is without a sense of history. There are places, like the Eiffel Tower or The Grand Canyon for two examples, that don't require a narrative to be understood. The Eiffel Tower appears immediately as what it is. It looks before-its-time (it was); it looks like it's made of iron (it is); it looks, in fact, like a grand French architectural "folly" (which it certainly is). The Grand Canyon also requires no narrative (although a viewing can be more pleasurable with one) because it's just so breathtakingly huge, and the bands of geological history stand out in such vivid colours even to those ignorant of their meaning.
Cities are sometimes like that, too. Prague springs to mind. Venice. Melbourne. Each making no pretense at being other than, and appearing as, exactly what they are. Sydney is different.
First of all, it was both an entire colony, and also, in the early days, completely a gaol. Most other colonies were, from inception, part of a larger plan. Not Sydney. It was the whole colony. The whole world for its inhabitants, who were prisoners and their guards. That is not to say that prison labourers were imported to work the fields, or some such, as elsewhere. The whole place was in effect a prison without walls. Not because it was set up to test some new theory in corrections, but because in a very real sense no walls were needed. For its early European inhabitants, Australia's wilderness, the bush, was simply non-survivable.
This initial use of the land survives to this day in Sydney's layout, which is completely opaque unless you know why. Why the urban sprawl onto the fertile floodplains to the west? Why the patchy nature of the city's population density? Why the (modern) sterility of the inner port and the steaminess of the outer port (opposite to most port cities)? All those questions have answers, but you need to know your history.
Second, if your view is confined to Sydney's CBD, it does appear to look a little imported, with your Starbucks and your McDonald's in plentiful evidence. But Castle Crag, Randwick, Bondi, or Newtown? Uniquely Sydney, uniquely Australian. And downtown there is also a particular Australian-ness if you simply look up; up beyond the street-level visual pollution of global chain stores. Up to Sydney's uniquely Australian blend of Victoria and Albert architecture and brash, confident, fusion Australian skyscraper design. This isn't Chicago, New York, or Los Angeles. It's Sydney, Australia. It could be nowhere else. But again, without knowing why this unique sedimentary built environment exists, it's hard to lift your gaze from the burger joints.
Last, but not least, Sydney is Australia. A multi-cultural melting pot sitting on top of land with enormous significance to Australia's original owners; the definition of Australia. Multicultural means more than this, but the most obvious outworking is that you can get any cuisine in the world here; and even better it will taste pretty close to the original, and in some very well known cases, better. That's Australia, and that's Sydney. To complete the picture, the symbols of Sydney are two out of the four visual images non-Australians have of the country. Australia's symbols are: the Rock; the Coathanger; the sails; and the kangaroo. Symbolic of the four ages of Australia, if you forget your history you forget all this, too.
Not without its faults, the most telling of which are entirely home grown and themselves products of history, the accusation that Sydney's somehow not Australian simply doesn't stick. You may need a history lesson to understand why, but Sydney is, in fact, the most Australian city of them all.
Postscript: It was my intention to leave the reader wanting for more, but a series of messages leads me to spill on two particular issues. 1. The "mirror reverse" of Sydney's port has to do with that great reshaper of cities, epidemic. Namely an outbreak of Bubonic Plague which caused much of the inner port to be levelled in the early 1900s, shifting the centre of gravity. 2. The "four ages" of Australia are pre-human, pre-European, European penal colony, and nation.