Earlier quoted context omitted.
If the robots have a longer working life than the humans they replace then they don't have to be cheaper. Doing physical work breaks down your body relatively quickly.
Yeah but humans expect return on investment before they die.
If you can sell stock, or leverage it for loans, then you get access to future profits as soon as there is a reasonable expectation they will eventually show up.
Amazon's growth model was based entirely on this effect for many years. No need for profits, company's value skyrocketed as anticipation compounded.