Are those not in opposition? Another solution is a better breed of business that doesn't see $ as the most important thing in the world, but not sure how you change that. Capitalism can and should be a conduit for innovation without outright greed.
I was working for a tech company that liked to pride itself on being "one of the good guys". They gave us pretty lavish benefits, that often seemed kind of silly, and had a massive well-designed office. Although the office was still an open office, and suffered from those aspects.
They recently had to lay off 60 of their ~200 people.
What would have been better? Should they have been greedier, given fewer benefits, and prevented the layoffs? Or should they have given more benefits, and not had layoffs, and simply collapse in bankruptcy in a couple years?
Money gives you options, and it is the tool which enables us to provide for people. I think your anti-greed position just... misses the point.
Not using a "massive well-designed office" would be a start. They probably didn't need 200 people, either.
If you will look at most tech companies, they are poorly run. Github lost $66 million in 2016 hosting code. You don't gotta be Warren Buffet to know that something is wrong with that setup.
The greed aspect comes into the everything needs to be big, because for too many companies the end goal is not the product, but money. That's greed. That's not just a failing of morality but a practical failure of building sustainable businesses.
They are in opposition in the same way 'we need to drink water to live' and 'don't drown' are in opposition.
Just because something is bad at the extremes doesn't mean it is always bad. We need a government that steps in to address the well known issues with unfettered capitalism (externalities, tragedy of the commons, etc).
No economic system can live up to its design when corrupt governments interfere with it.