Before the chokepoint capitalist: you go to a store and pay $20 for an average-quality product. The value chain benefits by getting $20, you benefit by getting the product. Mutual exchange of value.

After the chokepoint capitalist: the store has closed so you go to a website and pay $30 to receive the crappiest version of the product in 6 to 10 business days. The website gets $20, the value chain that does 100% of the work (the website didn't add value, just stuck itself in the middle of your transaction) gets $7, the post office gets $3, you get the product. Mutual exchange of value.

This "mutual beneficial exchange" stuff is like that xkcd alt text on free speech: it's as if the best argument you can make to support a political position position is that it's not literally illegal to express support for it. "It's a mutually beneficial exchange" is saying the best thing about a transaction is that it's not literally a scam. Seems we should aim a bit higher than that if we want a society that works, yeah?

This is the key insight.

Chant “mutually beneficial exchange” all you want but the system and its players have done everything possible to ensure that everyone at the bottom has as little leverage and as few alternatives as humanly possible.