Until the reality of budgets set in. IOTL, the RN had abandoned the two navy standard well before WW1. There is a big difference in talking about being able to defeat the two largest powers, and building the navy to do it. And this is based on prewar standards which had a good bit of hopium in them. I reality, the UK almost went down to one power using submarines. There is not way the UK defeats the USA and one other great power navy once that other navy goes to merchant warfare of some type. Now there is also no way the other powers stand idly by either.
This thread is basically discussing a military table game that can't occur because of diplomatic and political realities.
Well actually by WW1 the two power standard had gotten a lot easier, there was one, one power that could seriously hope to keep pace with the British in the dreadnought age and that was the US. However it would require further massive growth in its civilian economy before it could look to match the RN by simple domestic construction...hence the Washington Treaty. Germany found in 1912 it just could not afford the race. Without a nice handy European War™ the US has to wait a bit. It will if it follows its OTL trajectory find itself in a position of massive supremacy but in 1910 it is not there yet and in 1900 it is much further back. For example of the World's dreadnought fleets in 1919 almost half were British.
As to going down to one power, firstly that power had to use submarines and secondly the British did not go down...minor point but worth mentioning. In 1910 submarine tech is iinfancy but in 1900 it was neonatal.
What this thread could be is an exercise in trying to understand how sea power was built and maintained. Rather than simply assert something, try actually asking and looking to find answers for such questions as
1: How many cruisers does it take to blockade Britain from bases in the Northern Western quadrant of the globe? For example the estimate for the required U-boat force to bring down Britain was 212 boats, of which the Kaiserlich Marine managed to actually assemble and maintain a peak strength of 120.
2: How long does it take for the US to assemble such a force?
3: What kind of counter force might Britain build in the mean time? In the era in question the likely British response is a mixture of 1st Class cruisers to hunt and kill raiders, later this philosophy results in the battlecruiser,. 2nd and 3rd Class cruisers to defend commerce. Later on just after the era in question the Light Cruiser is developed and of course destroyers continue to mature.
4: How does the dynamic of British reaction affect US build up and strategy?
5:How would a credible US threat affect European diplomacy and power games. In OTL the US was the snoozing giant...it was not that giant at the beginning of the decade in question but in terms of civilian economy it was a lot bigger than anyone else by the end of it. Now give it a few more teeth and how to people react?