I find it is more the 5th to 8th income/wealth deciles being temporarily embarrassed 9th decilers, and wanting to believe they will possibly join the 10th decilers someday. The bottom 5 deciles do not have much hope of getting to the top in the first place, they are aiming to get to the middle deciles.

Everyone wants to believe they are marching upward, so if they or their children are trending up (no matter that they are probabilistically not likely to get near the very top), they still do not want to lower the ceiling.

I feel like this quote summarized a lot of tribal conflict, whether it be delineated along socioeconomic class or race or whatever:

https://www.snopes.com/fact-check/lbj-convince-the-lowest-wh...

Everyone is happy when the tide is lifting all boats, but when some are rising more relative to others, implying some are moving down relative to others, there is inevitable chafing as resources are re-allocated.