There’s a difference between making profit and becoming one of the richest person in the world, in the second case it means you clearly made too much profit by selling for a higher price than required.
Let’s play ball here too. So by definition there’s always going to be a richest person in the world - let it be with a difference of 100 dollars to the median or a billion dollars or 100 billion dollars. Who gets to decide who is the richest person and by what means? Clearly it shouldn’t be a business person so would it be a politician, a dictator, a president or who? And how should we restrict entrepreneurs getting there without destroying every company and therefore making everyone unemployed because there’s no incentive to run a business anymore? How would we balance risks with gains if we are not allowed to make a profit?
A richest person will always exist, there’s no reason why that richest person couldn’t have 500k in their bank account while the median is at 250k though.
The fact you’re setting an arbitrary limit of cash in a bank account shows how little you’ve thought about this. Rich people have money in the bank, sure, but the vast amount of their wealth is in stocks, property, and other assets. Also, assuming rich people have one bank account they keep all their money in is foolish. You have to spread your cash around to multiple accounts and even banks in order to not exceed the amount the government is willing to insure.
1.5 million is not a lot of money when you’re talking about the richest person.
You’re definitely right that you picked apart their argument because ackshually there will always be a richest person. But clearly the sentiment is that someone shouldn’t get excessive wealth past their threshold.
How do we define excessive wealth and how do we limit it? Well there are lots and lots of proposals I would suggest reading up on some (you can Google that question to get 10 op eds that suggest 20 different solutions). I wouldn’t mind defining it as a certain percentage higher than the median wealth of the country. It would be funny to give Gabe Newell a “you won capitalism” trophy and taking excess wealth he gains.
As for motivation. It’s a much murkier subject than you imply. In an economy where the state takes every penny of a successful business’s wealth, yeah it makes sense that there’s no motivation to make a successful business. But if one could still get rich off of running a business (just not god-tier level wealth) I’m sure there would be plenty of motivation. And hell, if we give them prestige like we do now there’s tons of people who do what they do just for the fame with no profit. There’s tons of evidence that people aren’t purely motivated by the infinite profit of business people all over the world work their asses off in jobs they enjoy or respect that will never pay them Gabe Newell bucks.