He talks about two benefits: One for the companies (profit and real improvements in productivity), one for the employees (better focus means less unpaid OT answering after hours emails and texts, or even paid OT that still leads to burnout). The reason to focus on that former one is that it's pretty much the best way to convince the people who care most about profits (that is, people at the top of the hierarchy) to care about something. Not that they don't care about employee wellbeing at all (though some may be truly uncaring), but it's too remote from their present position or too low a priority compared to keeping the company operating.
That's why he talks about how in this case he thinks incentives (in particular between management, shareholders, and employees) are actually aligned to potentially produce a win-win.
Not to mention he only describes the benefit in terms of dollars of profit to companies. Broaden your scope of the potential benefit to humanity!