That because of the weather in Russia and Scandinavia.
When are they going to play the Summer Tournaments? The calendar from July/August to May was already congested pre covid. Swapping it to March-Nov still doesn't give room to play a month long tournament. Now you can play it thru the season. Works in other sports but those sports also don't have the financial power that football does. Also big clubs wont want to compete in a league season without 7-10 main players for 6-7 weeks without being compensated. And we've seen the quality of football drop off in the last 6 weeks or so with the congested covid schedule which is what would happen if you suspend the season so they could play a summer tournament. Good luck in trying to get the big leagues to change to an 18 team league format.
Football calender from March-Nov effects the sporting landscape particularly the summer sports. No summer sports wants to compete with football every year in those countries where football is #1. Sports attendance figures will drop, TV money will be lost and so will general interest in those sports.
And then there is the end of season pre Christmas tours. Because their is a gap before Christmas to do so. The clubs wont care about their players workloads.