The reason I don't switch is because a 0.5L coke has around 210 calories. You're only supposed to consume around ~2000 calories per day, so even with 4 cokes in a day that's almost half of calorie intake. So not an option for me.
The problem doesn't seem to be just sugar.
I've found that the smaller 250ml cans is enough to satisfy any cravings.[1] Occasionally I take 2. Even with 2 that's 25% of what you are saying.
[1] http://blog.nawaz.org/posts/2021/Dec/taming-my-soda-addictio...