PG made the error thinking that this is just people misunderstanding math and exponential growth, which created a convoluted math section that could have simply been explained as - if you start with a million dollar and double every month, you'll be a Billionaire in less than a year. He also didn't really touch well on why many people hate large companies / billionaires.
You are making the mistake of using a moralization framework that equivocate being accused of something to being bad for society + not looking at the alternative (i.e. even if it's true that every Billion dollar company is "bad/exploitative/etc.", that doesn't mean that the (realistic) alternative is better for society or people.
The reality is that companies like Google, Amazon, NVidia, etc. have create an immense amount of wealth for their founders and investors, but also created an immense amount of value in society. There is a real problem of incentives when you prioritize growth endlessly, as it leads to perverse incentives such as that ones these companies are accused of - leading you to progressively take more and more less positive actions in order to achieve this growth. So I don't disagree with the general premise that growth leads to moral problems, but I do disagree with saying that building big companies is bad for society.