I wish I could pull it up, it had much more coarse grained categories than what you linked and long time periods. It might have been a meta study.
For example in one of the links they discriminate food away from home etc.
It's not the one I'm remembering but it looked a bit like this one: https://flowingdata.com/2018/02/08/how-different-income-grou...
It looks rather proportional. But I have to admit, here housing is fatter at the low and. Personal insurance/pension gets fatter the more you move up. Education is interesting as it is fat at the very low end, gets thinner for a bit, but after the lower middle gets fatter again continuously. It also cuts off after 200k yearly income, so there's that.
Where are you getting this from? It’s definitely not true when it comes to savings and investment. It’s not true for food, as I linked below. Its not true for travel. It’s not true for housing either. Why do you believe this?
https://www.ssa.gov/policy/docs/research-summaries/housing-e...
“Low-income families spent a far greater share of their income on core needs, such as housing, transportation, and food, than did upper-income families.”
https://www.pewtrusts.org/en/research-and-analysis/issue-bri...