Because it makes the final product taste better. You can reframe that to mean something nefarious (ie. "it's there is to increase [...] addiction"), but fundamentally it's not any different than you adding salt when you're cooking.
>it's not much, you won't even notice it
>Because soda contains several potentially habit-forming substances like [...] sodium
Let me get this straight. You're claiming that "you won't even notice it" yet it's also "habit-forming"? What's the mechanism by which drinking 0.2g of salt per 20oz bottle gets you addicted?
https://pubmed.ncbi.nlm.nih.gov/24829986/
A Classic Innate Behavior, Sodium Appetite, Is Driven by Hypothalamic Gene-Regulatory Programs Previously Linked to Addiction and Reward
https://pubmed.ncbi.nlm.nih.gov/29673924/
Food additives, food and the concept of 'food addiction': Is stimulation of the brain reward circuit by food sufficient to trigger addiction?
I don't doubt that salty foods in general are delicious and make people want to eat more. I'm doubting whether the effect applies specifically for coke, which only has 0.2g it per 20oz bottle. What you're doing is like looking at a car crash and concluding that it's caused by alcohol because the driver ate some bread[1] before driving.
[1] https://www.scienceabc.com/pure-sciences/does-your-bread-con...
I'm not pretending I'm the expert.
> What you're doing
I'm cited the source.
> it's caused by alcohol because the driver ate some bread
Don't tell our politicians ... we have 0% limit.
A source that fails to list what the dosage is, and I highly suspect isn't in the range of 0.2g/20oz.
>Don't tell our politicians ... we have 0% limit.
https://en.wikipedia.org/wiki/Blood_alcohol_content#0%
>It is illegal to have any measurable alcohol in the blood while driving in these countries. Most jurisdictions have a tolerance slightly higher than zero to account for false positives and naturally occurring alcohol in the body.
https://laborrights.org/in-the-news/2005-list-14-worst-corpo...
As you said ... it's not much, you won't even notice it. So the reason it's there is to increase consumption (to keep you thirsty and to tolerate more sugar) and addiction.
https://www.healthline.com/nutrition/soda-addiction
Because soda contains several potentially habit-forming substances like caffeine, sodium, and sugar or artificial sweeteners, it’s easier to become dependent on soda than you might think