The increased city values has sped it up but I guess Inno didnt adjust the WW requirement because they wanted worlds to be shorter. Maybe they have data that shows more people leave on long worlds, or more likely quicker worlds = more players starting new worlds = more gold for inno.
En70 was a pretty good length, about 1 year start to finish. That was long enough for some good wars, for loads to happen, even the mid ranked players could get up to 40-70 cities and was long enough to get to know people on your alliance, and things to develop diplo wise etc.
US42 (Speed 2) started late november and is about to go into WW in the next month, 6 month server, total joke, En81 looks like its going to hit wonders in 6 months or so since the start of the world. thats far too short an amount of time for people to be playing together (and actually encourages mass cuddling for wonder phase).
Almost makes you want to play speed 1 just to get 12 months gameplay out of a world.
I would agree with you if I hadn't played US34 - Juktas. Exact same settings as sinope, except it was released in 2014 so 13k cities.
It is now 13 months old and one of the most stagnant worlds I have ever played in. Islands all over have 2-3 cities on them, the top 2 alliance branches account for probably 80-90% of the points in the top 15.
It was so boring, one of the reasons I stopped playing it.