I know, and the one that says 56% pay their balance every month was only 1000 subjects. The others show very different numbers.
1. Agreed that it is a small sample size but none of the quoted items state what you indicate.
2. The sample size of 1000 says the largest group paid their bills in full each month
3. The 56% figure was from a different data set and it referred to accounts - not account holders. Perhaps or perhaps not is is safe to assume that people who don't pay the balance in full may be carrying balances on multiple accounts.
In any event it seems 50% or so of Card holders may pay in full each month. As far as changes in balance size over time adjusted for inflation - I did not find any simple data. Point being - things seem not nearly as dire as some might have us think. However I for one feel the worst pandemic / addiction is borrowing - from the highest levels of government down to individuals.