To the contrary, I find it odd that there isn't a single upper-tier livable city in the western 2/3rds of the US but every city in the eastern 95% of Australia is top tier. Hell, my neighbors immigrated from Australia.
The problem also is the laid-back culture which creates mediocrity in my opinion, the tech scene in Europe, America, Singapore is much better as a result.
Depending on priorities its a great place to live, but if you are super passionate about whatever you are doing, it may not be the best place to advance career wise.
And frequently people move for bigger money or career opportunities over livability.