What the capitalists did was pay all the workers right after they did the work, even though the phones wouldn’t actually be sold for some time after that. Capitalists bring capital. Money. It takes money to get things started.
I completely agree that the rewards are all disproportionate. The people who put up the capital shouldn’t get all the rewards. But it’s just dumb to claim that they play no role at all. If that’s true, walk out of your house and make a phone you designed yourself out of sticks you find on the ground.