I'm not sure that UTXO size distribution tells us that much about wealth distribution in bitcoin.

Almost half the UTXO set is made up of UTXOs with less than 1000 satoshis. These probably aren't people who are trying to hold bitcoin, but rather inscriptions, runes, and the like or just dust. I guess it doesn't change the meaning of the chart much, but it is probably more weighted toward the middle than it seems.

(chart: https://research.mempool.space/utxo-set-report/)