Everything has a use, but as computers, ie smart phone usage accelerates, desktop usage goes down. OSes shed function and must get lighter weight and respond to user inputs fast.
I built my first computer before there was a PC ... We first did it with discrete components, yes it took lots of cabinetry, and then used the 4004 ... then the 8080 ... And now well it’s too much trouble to build.
In a few years, I doubt there will be many desktops being sold. Have you looked in Best Buy lately? Almost all lot-tops and smart phones. People want to do things ... The next big step, away from laptops, appliance computing on the go, is on the horizon.
The Mac was the first computer conceived to be a consumer computing appliance. 20+ years later Apple finally starts to make it happen with the iPhone then iPad.
Power users will always want PC's. I spent the last 5-1/2 years creating and maintaining a 3,000 page distributor catalog and the complementary website. I batch processed the images for conversion (at one point over 80,000 images for the 2 companies using the system. + thumbnails.) All data for the catalog sections and the company promotions were scripted from an AS400 database to my PC. Then it was organized in Access and into Excel, exported as a tab delimited text file and imported into Quark using Xdata (or Xtags). Anything that scripts image composition or batch processes images requires extreme resources.