From a health standpoint its like arguing the relative merits of 3 packs a day of smoking vs 3.1415 packs a day, "eh".

Also unit dosage for virtually all consumers is the unfortunately somewhat variable can.

Yeah... back in the day, us kids would try to find the soda with the highest cane sugar content. Now, I try to find the lowest net carbs in everything I eat or drink. Arguing about 33g vs 40g in a soda does seem non-productive.

Europeans buying a coke can in the US will not stop at the 330ml point. They are gonna continue drinking until the can is finished.

39 g is far more representative of the overwhelmingly likely sugar consumption in the US than any per ml measure, and far more useful when discussing diets.