I wasn't able to find anything like "average car payment for low-income Americans", but this link shows that average car payments are pretty evenly spread across the credit score spectrum, with rates inching up as you go down, probably because of higher interest rates. No idea if credit score is a proxy for wealth though.
https://www.cnn.com/2023/04/15/cars/car-loan-interest-rates-...
A ton of concerning stuff here, most notably that two-thirds of these loans have 5.5-7 year terms now, compared to 30% in 2004. The article it links to shows that for 2023 Q1, the average term is 70 months, down payment is $4k, APR is 11.1% (!!!!), so that the monthly payment is $551 even as down payment increases and amount borrowed decreases.
Again, I don't want to say you're wrong: you can find cheap cars, people survive with clunkers. And the most frustrating part about searching this is that I haven't been able to separate the rich people buying Escalades from the poor people buying entry-level vans, so I don't have a sense of demographic makeup here.
But all of the trendlines are pointing towards car payments being bigger than ever and terms longer than ever. Mash that up with higher interest rates and some lingering supply constraints and it's not a healthy market right now, which is why it doesn't surprise me that people are yearning for a different solution that doesn't involve a heavy reliance on cars.