In OZ they may have some cost benefits from the competition, but their ISPs all do usage based billing (metered internet), which is just another way of stifling growth and protecting old business models and reducing the need to improve the infrastructure.
Meanwhile, if you are lucky to live in a Google fiber served community (3 cities now, a few dozen coming soon), you have 1000mbps to the home.
Business and government forces will continue to shape our online experience and given few understand how any of this works, they get away with policies that stifle progress and innovation in order to protect their interests.
These things do erode over time. Just look at smartphone plans: I never got one until last year, because ATT wanted $150 per phone per month and I have two teenagers. However, since last fall, I am paying between $35 and $45 for three smartphones combined, because I use a carrier who resells excess bandwidth of the big name phone companies without the free device perks and other limitations, but they do exist (Ting, Virgin Mobile, etc).
Unlike wireless, the problem with broadband is that in most places people don't have a choice like you pointed out. This may be changing, too, but slowly and only regionally (meanwhile the big companies are merging to become even bigger).
For example, in my home town the municipal water & light utility is investigating fiber to the home home, justified as a infrastructure investment mostly. They have seen what fiber did to business development in locations like Provo UT.
Speedtest - don't be fooled by those numbers. All this meters is the throughput you are getting from your device to the nearest Speedtest server, bypassing protocol based throttling and all the downstream congestion you may be faced with trying to access content that's not hosted near your home in a cache box at your ISP's local data center (they may or may not have Netflix cache appliances there, and then not all content is on these caches - don't expect that foreign art movie to be hosted on a server nearby...).
Given the bandwidth we are quoted by ISPs and measure with Speedtest, we should have no problems with 5mbit full HD content at any time, but Netflix stats show that in the US, we are far off from that bandwidth, no matter what your ISP is telling you about your connection. They take their numbers from actual access data which is real world data, not "up to 60 megabit" adverting BS:http://ispspeedindex.netflix.com/results/usa/graph
Note how Comcast has dropped 25% since October 2013, before the courts gave it green light to do whatever they want with traffic on their network.
Bandwidth shaping isn't new - cable companies have done it forever, with their asymmetrical connections. However, they are getting more and more sophisticated, well beyond "slow down bit torrents to 100kbps" brute force rules.
For example, to make your connection appear snappy fast, even the slowest 18mbps cable plan where I live will reach 60mbps for the first second or two - enough to have web pages load in a hurry. However, the moment any request continues for more than a few seconds, the brake is pulled and your download speeds will quickly approach the limit you are paying for, and then the ISP may slow it further based on content and origin to reduce their costs or reduce load on their shared infrastructure.
Over time, things do move forward: 5 years ago Netflix wasn't even thinking of streaming anything over 1.5mbps, but now they do manage to squeeze through the occasional 4mbps stream, which still stinks compared to what real "high definition" video requires, but consumers are completely youtube desensitized when it comes to video quality