If somebody developed a drug that allowed people to go without sleep indefinitely, without immediate cognitive impairment, these companies would offer that too. It would be "voluntary" of course, but people who went without would have a hard time advancing or even getting good reviews when they're compared vs. the sleepless. Then we'd probably hear ten years down the road about how the companies were quietly finding excuses to let people go before the long-term health effects kicked in.
Isn't it great that these cutting-edge companies can offer such empowering choices to their workers?