If Capitalism was the default, you'd find it among apes. Instead Capitalism is a recent invention and it's always evolving towards stronger concentration of wealth.
But let's recap.
By now we know that wealth generation (by technology) doesn't prevent its concentration during distribution and how such concentration subtracts such wealth from being distributed (by definition).
Just like a dam at the river head, people concentrating wealth subtract to those who would get down the flow (think of Bezos and #Amazon employees).
Furthermore you accept that people are not rational agent: they are continuously manipulated through their biases (the "behavioral futures" that #Surveillance capitalist trade) to buy products they don't need (thus NOT generating wealth, but giving away their own wealth).
Also (as far as I can see in this thread) you don't contest the fact that corporation aren't rational either as they optimize one single scalar dimension, profit: the net wealth built by corporation that maximize profits is negative as soon as you take the externalities into account.
Now the point of a #UMW (Universal Maximum Wealth) is not to punish anyone for harming anyone else. And it's not even a way to turn irrational people into rational one! (for that we need education, with a strong focus on #History and #Informatics, see http://www.tesio.it/2019/06/03/what-is-informatics.html)
UMW is just a way to build a simple and effective incentive system designed balance #collaboration and #competition.
One the drive to accumulate more wealth is balanced by the need to increase the wealth of everybody else, corporations will have fewer and fewer reasons to fool people through #marketing.
So while people will stay as irrational as they already are, there will be no advantage to exploit their bias.
In that context, #AdamSmith's #trust would be possible again, raising the probability of actual wealth creation by rational trades.
Basically, in such framework Capitalism could probably work.
Now, you see all this is flawed, but you didn't explain (or I didn't understood) how.