Pete, there used to be a 4-minute standard... you don't even consider it now (it's not in the poll options).
The point of the poll is to simplify the work of the organizers and create common rules.
And you can always agree on a shorter time in a season, especially since the limit is the same for both players ;)
The time limit also has an impact on the game's tactics; if there is little time, the whole game will be structured differently.
Yesterday, I played a balanced CM with a 10-minute limit. In the third week, there wasn't enough time - 7 cities, 2 mammoths, a lot of battles, I was moving troops and artifacts across the map. On my turn, I wasn't thinking, I was just trying to do what I had planned on the opponent's turn.