Chromebooks are an US school phenomenon, hardly spotted anywhere else.
I can only speak for the US market I guess, but they haven't found a real need for a PC/Mac outside of what a Chromebook can do, so at the end of the day, I don't feel it bodes well for PC/Mac long term.
I'm a developer at work for internal applications (and some external). All of my non-server running things are web applications. They could be accessed by Chromebooks instead of the hp Windows 7 laptops we use now. I doubt we'd switch off PCs due to familiarity at the very least, but we don't need them.
That being said, I will eventually die. Now, the question becomes what are the people that follow after me going to be using. I have kids in school: both use Chromebooks for school work, in one case a PS4 for gaming, and hand-me-down iPhones/iPhone SEs for social, gaming, and the like. Could they eventually need a PC? Possibly, depending on their career path/interests and the level of support for iPads, Chromebooks, etc. at the time. But they don't need it now. And I know people who are my age and older who limit themselves to iPhones/iPads for technology beyond the TV. None of these things are running Windows.