I guess some elements of capitalism need people with your defeatist outlook, to be lifelong wage slaves.
There are a lot of as you put it "wage slave" businesses which have 45 people making barely enough to live 4 folks making 20% more in semi-supervisory positions working 60 hours a week with lots of unpaid overtime effectively making less per hour than the grunts and 1 guy making a decent living.
You can accurately say that any of the guys could in theory move up but the logic breaks down trying to apply it to the group as a whole with one position essentially worth having anyone COULD move up but EVERYONE never could.
Society is essentially so constructed in the large. We can't all sell each other financial products. If we want society to function we will have to have a whole lot of people who are modestly compensated and I don't just mean french fry cooks. There are a lot of positions that are both challenging and necessary that really aren't paid that much. These people aren't all stupid losers and they aren't all too stupid to be business tycoons. They fit into the slots that society made and if we want people to move up we ought to do a better job at creating such slots and allocating resources to them.
Bemoaning the fact that people haven't pulled themselves up by their bootstraps is basically useless.
What business did you start?
This or worse is about half the country
You need expertise, time, and money to start a business. The majority of people lack not one but all 3.
This is probably why only 9% own an established business. Indeed jp Morgan says that future business owners on average start out substantially wealthier.
https://www.jpmorganchase.com/institute/research/small-busin...
Which supports my assertion that the majority are ill positioned to start a business.
Money buys time, money buys relevant expertise in, wealth makes risk tenable because failure doesn't mean homelessness, money and financial health in fact buys access to borrowed money.
Everyone could just do what only 9% of people do is an incredibly privileged thing to say it's like Zuckerberg saying anyone can have a website or bolt saying anyone can run.
It's insulting.