If you check Coke's financial statements, you'll see that although revenue has risen quickly, cost of revenue has risen about as fast, leading to relatively unchanged gross profit margins (36% so far in 2022, compared with 40%+ in every year from 1985-2014 and between 33%-39% from 2015 to 2021). Word from industry press is that the rising price of aluminum has been a major driver of the increased costs.

I don't know why pricing for the generic brands wouldn't increase as much. Perhaps some stores see the large price increase in branded soft drinks as an opportunity to get people to shift to the store brands and are willing to tolerate lower profit margins to see if that strategy pays off.