Capitalism isn’t you buying a tool and using it. It’s buying the 3D printer, paying people to design and build widgets, paying people to sell the widgets, then taking most of the money for yourself.

Yes, I agree that this should be possible. Of course, if I'm taking too much money, the capitalist system will encourage my competitors to defeat me. Meaning that there a dis-incentive in place for doing bad/selfish things. Sounds like a pretty good system!

I hate that I can work (with others) to build a company from the ground up and have nothing to show for it, because the owner is using us to fund his lifestyle. I hate that landlords can buy up all the homes, driving up the cost to the point no one can afford one, then rent them out and sit on their ass while I pay their mortgage. That’s capitalism. People profiting off of ownership. It inevitably ends with some people owning almost everything, and the majority owning nothing.

Yes I agree! I hate these things too. But capitalism doesn't prohibit every bad thing. Bad things can still happen under capitalism. I'm just saying that such things are harder to do under capitalism than any other system. For example, you mention landlords have to buy up every home before they can take advantage of you through their monopoly. That's way harder than other systems, where the government already owns all the homes, and can simply drive up the cost whenever they want :/