First of all hello everybody

After long time only reading here, I would like to contribute some thoughts about this.
As mentioned before by others, a simple system is always preferable if it does the job sufficiently good. In my opinion this works well for Culture / Faith and Gold, but Science and Food have to be treated differently. Thats why i would change
crdvis16 numbers in a way that ally-yields are always double the friends-yields and that the increase per era is increasing by 1 for friend-yields in the most instances (and the double for ally to stay consistent)
Culture / Faith and Gold get the same (for sure gold is the least valuable out of these three, but this is compensated for by the extra happiness):
Ancient 2/4 (was 1/3, 3/6, 1/3 for C / F / G)
Classical 3/6 (was 1/3, 5/10, 1/4 for C / F / G)
Medieval 5/10 (was 4/10, 7/14, 2/6 for C / F / G)
Renaissance 8/16 (was 4/10, 9/18, 3/8 for C / F / G)
Industrial+ 12/24 (was 10/22, 12/24, 4/10 for C / F / G)
Science is basically doing the same, but set one era behind due its value in combination with the extra units (science is a nice addon, but i think the main reason to compete for militaristic CS should be their units):
Ancient 1/2 (was 1/4)
Classical 2/4 (was 2/6)
Medieval 3/6 (was 4/10)
Renaissance 5/10 (was 6/14)
Industrial+ 8/16 (was 10/20)
For food i am a bit unsure but maybe this way every era step could have its benefit:
Ancient 2/4 secondary 0.5 (was 3/6 secondary 0.5)
Classical 2/4 secondary 1 (was 3/6 secondary 0.5)
Medieval 4/8 secondary 1 (was 3/6 secondary 0.5)
Renaissance 4/8 secondary 1.5 (was 4/8 secondary 1.5)
Industrial+ 6/12 secondary 1.5 (was 4/8 secondary 1.5)
Whether yields should go on increasing after industrial, i am unsure. Yes, CS yields get more and more unimportant, however i still go after CS allys, but that might be mainly because of my preference to play diplomatic games.