The power progression in this game is so bad. This was a super-minmaxed run where I used every trick in the book to outgrow GB, and only succeeded in doing so in the 1880's. Notice the GDP difference between the #4 and #3 ranked power (Russia and Super Germany) is literally x5 times.

Do you know why GB is so strong now? Because economic growth in this game is exponential, and they are strong enough to reach that inflection point which gives them infinity growth. They don't even run out of pops, since they get Indian migration plus the Chinese they inevitably conquer. I'm not sure why the hell the devs designed the system to work this way.