Sporting boundaries have not changed much since the introduction of mass media. There are changes, american football has grown in the USA last hundred years, but it was the primary form of football in the there even back then.
100 years ago, rugby league had taken over as the main form of football in Queensland and NSW, while AFL was dominant in Melbourne. In Britain, football ruled in Scotland and most of England, apart from some rugby league towns and the fee-paying schools and the Englsih South West playing rugby union.
In many ways, the lack of spread of sports generally is the question. A few that were in steep decline have declined futher, such as shinty.
It does seem that when mass media arrived, sports stopped competing as they had before and whatever sport dominated in an area remained that way. It was the first time hype became an issue for the major sports. This may also explain why where rugby league has spectacularly succeeded in PNG is where there was no mass media, which would have preserved the status of that sport.
That is pretty much why rugby league has survived. Then we have the things that have been against us. I often think it is very difficult to communicate the antipathy that the national media have often has towards rugby league in the UK. You may not feel that you have had a fair shake, a little over ten years ago there were many people in the south of England who genuinely believe that rugby league as a sport had completely died off - as in there were not teams in the world and no person played it. Imagine the media disinformation necessary for that.
Equally, the British had rather a large empire. Rugby union has a small presence through much of the world through diplomatic connections. Rugby union automatically had many people with money around the world to set up a token presence. The British army also helped spread sport, which meant the officer class sport, which was rugby union. Then, there was a significant wave of anglo-philia after World War 2, which meant that British sports got a leg up. Those sports were rugby union and cricket.
If you came to a new country and wanted to start rugby league as recently as 1980, how would you do it. First, you could start with the local rugby union club, but they would be banned if they were involved in playing rugby league. So, anyone with an interest in rugby football would be banned if they started. So, you obtain two sticks and attach it to soccer posts and that will do.
Next, you need the expertise. Any rugby league coach is likely to have a nice position in the rugby union club and may not want to give it up for nothing. You also have no refs, no locals have seen this game at all and it would be hugely difficult to show them what it looks like (no DVD's or Youtube).
Despite all this, you manage to set up a successful competition. Hooray! You write a letter to the RFL or the AFL and look forward to support, as the IRB are offering huge amounts of cash and support to switch to rugby union. What happens? The RFL and AFL tell you to send them money and stop bothering them.
There can be enough to make it work in places like London, but we compare ourselves with a sport that has been given huge articial advantages.
