The bigger issue is weak competition. When a few companies dominate a market, they can raise prices, suppress wages, and capture more of the gains from economic growth.

That is also a big part of why wealth has become so concentrated at the top. If there were ten real cloud competitors, eight GPU makers, or several serious Office competitors, those companies would have a much harder time keeping such a large share of the profit. Instead, concentrated markets create enormous profits, and concentrated ownership turns those profits into enormous fortunes.

In my opinion, that has a bigger impact on the bottom 90%, and even on the upper middle 10% you are talking about, than the direct consumption of the top 10% ever could. It would be much better to raise the purchasing power of the bottom 90% than to reduce the consumption of the top 10%.