You can view the effect of "that old trope" here.
As you can see on the graph, PCs hit their maximum sales year in 2011, and have been on the decline ever since.
I totally agree that PCs are the best. I have three in my home office, and two laptops for work. I would hate using a tablet for just about anything.
But that does not change the fact that tablets and light computing units are replacing PCs in almost every customer-facing job, and tablets are now a favorite of non-IT home owners because they are less complicated to understand (and not having Windows makes their maintenance a lot simpler). Not to mention all the kids who won't even know what a PC is until they get to school, madly typing their SMSes and watching YouTube as they are.
So yes, like it or not, PCs are going to be reserved to the (relatively) small group of people of actually need the power, group of which I am part.