Yes, the bottom quintile has a lot more variance, but the argument that the poor are being left behind has been really hard to make for the last 5 years. Coupled with high inflation, which erodes the savings of the rich, they're actually getting a bigger slice of the overall pie.
https://fred.stlouisfed.org/series/CXU900000LB0103M (26%)
https://fred.stlouisfed.org/series/CXU900000LB0104M (23%)
https://fred.stlouisfed.org/series/CXU900000LB0105M (22%)
https://fred.stlouisfed.org/series/CXU900000LB0106M (17%)
Yes, the bottom quintile has a lot more variance, but the argument that the poor are being left behind has been really hard to make for the last 5 years. Coupled with high inflation, which erodes the savings of the rich, they're actually getting a bigger slice of the overall pie.