Linux will likely outlive all of us. Network effects are massively strong for operating systems, we've been stuck with the same basic 3 for decades and that's likely to stay the same.
Mobile operating systems such as IOS have become huge and they're many new industries that look promising (my guess is IOT based one like alexa and Google home but who knows).
There are two major mobile operating systems, iOS and Android, both based on Unix clones, one on BSD and one on Linux. Mobile has dramatically increased Linux usage; what do you think Android is?
However, ios makes most of the mobile profit just as windows and Mac do over Linux for desktop (I have only used Linux in server industry so I don't know how they fair in those markets too much).
In that light, How about this prediction.
Linux will continue to dominate in the server market for a long time as businesses factor in the cost of os licenses and the supply of linux users is big.
Consumer markets like desktop, mobile, whatevers next will flock to the lower personal cost (through customer time investment in learning the os).
Well, it might happen that Google will fork Linux into their own thing, and it will be harder better faster stronger, and for some reason hard to merge back into Linux. And the ecosystem will move.