Firstly, if that is your biggest concern, then we agree far more than we disagree and we're quibbling over details (which I'm happy to do).
Secondly, who said they do?
It of course depends on what you mean exactly by a"slice of the pie" but there's lots of ownership models to choose from. Direct ownership is one. An employee owned trust is another. These are to a large extent solved problems - mutuals and co-operatives walk among us now, after all.
Thirdly, you mention the risk of setting up a company. If you're not rich, why do you have to gamble your dignity and livelihood to participate in innovation? Would the world not be a better place if you could invent and create and innovate and fall back on a basic income if it falls on its face?
Finally, even if we accidentally make things a bit too equal by giving Jim the new starter the same voting rights as Bob the grizzled veteran - is that not better than the system we have at the moment where incomprehensible hoarded wealth is concentrated in the hands of a few?