Why would it kill PC? There will always be hobbyists, e.g. I can't imagine pro e-sports players running on a Mac. Personally, half of the reason I moved away from Windows is Microsoft stalling/degrading Windows experience.
Price of PCs causing a collapse in demand, then mass bankruptcies of companies making PC components so supply chains get demolished and when prices come back down there’s no one left selling anything so you can’t build a pc at any price