There's a lot of narrow-sightedness in this zero-sum model of transactions.
In a properly functioning market, the limiting factor is competition. A business can't capture 99% of the "better off" because the guy down the street will undercut it by only capturing 98% and all the customers will go there. A customer likewise can't capture 99% because the business will decide it's not worthwhile and sell to customers who capture less. Somewhere in the middle is found equilibrium.
Bag-holding is different, it means there's some sort of trickery and the other side doesn't actually benefit from the transaction. And this does happen, but it's not the norm. Again, go take a look at your local shops. Which ones are engaging in this?
I'm not anti-capitalist, I just acknowledge this as a fundamental part of the human process. It might even be the case the businessman's incentive don't fully align with the stockholder/owner's incentive, in many case the businessman can profit at the expense of the company by capturing higher commission with side-effects that the company won't understand.
A clever businessman will get the better end of that, while still leaving his customer better off than if he hadn't transacted at all, as many witness at the car dealership.
That is not how the current US administration seems to see (foreign) trade. :)
When two people make a deal, voluntarily, at least rationally (unless it is charity) both expect to be better off.
The magic of the businessman is to connive his way into getting the largest slice of the 'better off'. He generally can't legally make a deal without generating value, but if he can capture it to the point the customer is only one iota better off he is a good businessman and no one has been defrauded.