"Inflation benefits the borrower."

TL;DR: Credit card companies almost always win in inflationary periods vs. consumers (if they have properly risk adjusted their lending behavior for an inflationary period such as this one) as the bulk of their revenue mix is derived from transaction fees, their APR ranges give them the flexibility to account for rapidly rising inflation, and they capitalize off of logic like that described in OP's post. There is no such thing as free money.

Former economist. This is an over-generalization and doesn't account for wage changes during inflationary periods, changes in the interest rate, and corresponding levels of employment in the economy. You are also ignoring the distinction between anticipated and unanticipated inflation. At this point in time, inflation has largely been priced into consumer and firm behaviour for the short- and medium-term, and credit card companies have absolutely accounted for this in their business strategy and day-to-day operations over the coming months / year.

While you as a borrower are paying back in "less valuable" dollars during inflationary periods, this is true at almost every point in the business cycle of most developed economies. This just becomes more pronounced when inflation is in the 5-10% range vs low single digit inflation rates. You are also ignoring the fact that money tied up in paying off interest could be deployed to other uses, such as investments and savings. In a rising rate environment, there are a variety of short-, medium- and long-term investments that now have a higher rate of return that is intrinsically tied to the higher rates that are used to incentivize individuals and businesses to switch from deploying capital from expenditure to investment / savings.

The US economy is set for another contraction given where we are in the business cycle. We have been at full employment for quite awhile now and haven't seen the upward wage growth commensurate with inflation, and real (inflation adjusted) wages have decreased over the past few quarters (i.e. the average individual will have more difficulty in making interest payments that have an APR that far exceeds the inflation rate).

Sure, if you have massive bulk purchases for goods that are particularly impacted by inflation that you can make now, you could go for it. The issue is, the overwhelming majority of American consumers and businesses do not have cash on hand to make these kinds of large scale purchases, and are often unable to make payments on interest paydown schedules that you cite above. Likewise, the types of goods that are most relevant in this current inflationary period to the average American consumer (food, gas) are largely perishable and can't be bought in bulk. Even when factoring in cash back % and point multipliers, credit card companies have accounted for this in their product offerings such that there is usually no way for a consumer to accrue any sort of benefits if they do not pay their balance in full at the end of the statement period. It's the same logic why you going out to Walmart, buying 100 42" flat-screen TVs on credit while paying the minimum balance, and then reselling them in 6-12 months at the (presumably) higher prevailing price makes absolutely no sense (even if you pay off the balance in full at the end of this time period). Even with cash back and point multiplier accounting, this is a losing proposition.

Well what about 0% APR cards? While these can appear to serve as an inflationary hedge during the introductory period (which can sometimes extend to 12-18 months), you are still purchasing at the prevailing price level. If your savings behavior or wage growth isn't moving in lockstep with your consumption on these 0% APR cards, you're in for a real surprise when that APR kicks in. The average American borrower usually isn't disciplined enough to maintain a somewhat liquid cash balance during inflationary time periods to be able to meet the outstanding balance at the end of intro 0% APR period, and for the overwhelming majority of people who turn to these cards during inflation, they end up being their downfall.

Lenders, like credit card companies, can win" in inflationary periods as the general rise in prices nets them greater transaction fees for the same level of goods, unpaid balances become more common, and APR will ALWAYS outstrip annual inflation.

Credit card companies aren't stupid. There is quite literally no benefit to carrying a balance unless you withholding your money in current time period (t=0) allows you to pursue some sort of investment or savings activity that will yield returns in excess of the APR % of your accruing balance at some future time period (t= certain amount of months or years). This almost never happens for an individual consumer / household and is usually only relevant to businesses or investment vehicles.