For an economy built on consumer spending this means that you get more economic growth by giving those rich people more money to spend, not by lifting up the other 90%.

You've gone and mixed up correlation and causation here.

The top 10% arent spending 50% of the money because they are the glorious saviors of the economy, protecting and nurturing it while us poor people thoughtlessly hoard and save all our wealth. It's actually quite the opposite.

this means that you get more economic growth by giving those rich people more money to spend, not by lifting up the other 90%.

This is probably true for industries like fashion, but I disagree with this point applying in general. There is only so much food, gasoline, and paper products an individual is willing to buy, no matter how rich.

The restaurant industry, for example, would collapse as we know it if most non-wealthy people suddenly don't have any extra income to spend on prepared food. They need velocity in orders just to remain open at all. I doubt most places could remain open off of a few rich people buying a lot.

This isn't to say that they won't stop extracting more from the lower earners. Many of them would be fine killing off industry if it makes themselves richer. I personally think all of it's a short-sighted cash grab that's gonna keep poisoning the economy until something changes.

Except they could still do that level of spending while not perched atop a massive hoard, and the rest could do cumulatively more spending via their sheer numbers if said hoard were distributed more evenly.

Trump45 term benefitted signifciantly from QE based suppressed low rates that inflated financial assets, and so made rich people richer without creating inflation as wages and jobs were flat (until way down from covid mismanagement). He/sycophantic media could boast about economy without improving people's lives.