I always got hung up on that too. It seems to me that the ideal state would be you invest in a company, they make a profit, you get a share of that profit. You can reinvest that in other places, helping more people start their businesses, helping more people find employment and get things done. It's like economic democracy in action, where people get to decide what businesses are needed through investment. No person on Earth should have the funds to just build a chip fabrication plant, as an example, so crowd sourcing the funding like this makes perfect sense to me.
Where it falls down is in short term greed. I don't think that the system was intended or can reasonably sustain all the high-speed trading trying to maximize returns not by helping the company succeed but by leeching off of the investment of others. What should have been a way for people to help build things has become a way for a whole industry to extract more money out of the world.
I don't know the full history of corporate shenanigans, but it's my understanding that the beginning of it all was to help form businesses that no individual could afford to start. No single person should reasonably have the funds to build a factory with all of the expensive equipment and parts needed to make cell phones. So you get people together who think cell phones are a good idea, they all pitch in, and now you can afford to build it and they get to share in the profits when it succeeds.
I like the employee-owned idea, but it seems like it would be hard to get off the ground in industries that require huge upfront investments. Imagine you want to build a grocery store, but the land and the building and the initial stock all takes money so you have to ask the cashier for $10,000 up front before you can actually build the thing and later start paying them. I legitimately don't know, are there proposed ways to build these businesses but make them employee-owned?