I guess the question is are saving rates low because of mortgages or because of CC debt? I'd tend to lean toward CC debt, as a good chunk of the population doesn't even have a mortgage, the cost is typically fixed, and you don't take out an extra mortgage to pay for 15% inflation in food, you put it on a CC.

CC debt is also far more damaging to household finances, particularly during high inflation as you're just piling ~%20 CC interest rates on top of the inflation rate. So a "return to normal" is going to be far more damaging in 2022/2023 conditions than it would be in 2019 conditions. There's also no indication that CC debt is going to level out, the "normal" in 2019 was an upward spike as it was, and inflation is likely going to continue due to structural factors, which is going to continue to force people to compensate, which likely means an even sharper increase in CC debt.

Getting back to the potential railroad strike, put an extra 10% inflation on top of everything and for many people that's another 30% after they put it on a CC they can't/don't pay off. For many households it would appear we're looking at literally exponentially increasing levels of debt, mostly fueled by CCs and high inflation. That's a crisis.