The Greater LA areas has 34k square miles of area. Germany, the whole country, has 128k square miles. In other words, the LA area alone is a quarter the size of all of Germany.
https://en.wikipedia.org/wiki/Greater_Los_Angeles#Urban_area...
This isn't a size measuring contest. I think Europeans forget how _young_ America is. That's the only unique part of this country. Give us a few thousand years and we'll be on par.
Looking at the population of greater Melbourne has you looking at suburbs like Werribee, Frankston, Boronia, etc., which everyone would consider as a part of Melbourne (suburbs, outer, but very much a part of the core).
On the flip side, the "Seattle Metropolitan Area" consists of:
Mt Rainier. Bainbridge Island. Glacier Peak in Mt Baker Snoqualmie National Forest. Mt Vernon. Olympia. North Bend.
No Western Washingtonian is calling any of those locations "a suburb of Seattle".