Even your source says a minority of Americans (even though it again, cherry picks from that study).
The actual statistic is that when asked if they could cover an unexpected 400$ bill - 40% of Americans responded that they would sell something to help pay it OR couldn’t pay it.
Secondly the survey itself admits that it had an, “oversample of individuals with a household income less than $40,000 per year”
https://www.federalreserve.gov/publications/files/2017-repor...