That has already happened, lol, and the real alternative was... linux. There are several improvements that have come about because they appeared in linux first.
But I'd be at it for a year just trying to get all my graphic arts stuff to work.
Then you have to start on the games and sound editing, etc.
Graphic arts? If you mean specialized fields such as 3d design suites that interface with and control very expensive CNC milling machines, then sure, I'll agree that the options are somewhat limited - but then again, there aren't exactly hundreds of such apps for the Windows environment either - and that not all of them are free. But if you mean more mainstream things such as "simple" 2d or 3d design work, architectural design, desktop publishing, photo restoration, CGI/animation from the simple stuff to motion picture quality output, et cetera... Then there are certainly alternatives. For everything that can be done in Photoshop, for example, you might take a look at Gimp and the many plug-ins available for it. Being a powerful app, there is of course a learning curve - but the same can be said for Photoshop.
The thing with Windows is it runs everything.
Uhh... No. Windows runs applications that are written to run under Windows. My Chevrolet accepts parts that are designed for it and my Subaru accepts parts that are designed for it. It is not a failing in the Chevrolet that it cannot accept a Subaru bumper, and vice versa. I suppose I should point out that there are emulators available for both Windows and linux OS that allow one to have a virtual "copy" (+/-) of other computers, operating systems, and game-consoles. The list of emulators written to run under linux OS is, however, FAR more exhaustive than the list of emulators written to run under Windows. There are actually ways to run linux software under Windows, but as there is more work involved and the degree of success seems to be somewhat less successful overall...
NO one OS is capable of running "everything." But when it is a case of which one is capable of running more applications, I'd give the nod to linux.
It has it's shortcomings but unless you are running a Mac it's the only complete operating system, love it or hate it!
I'm not sure what you mean by "complete operating system," but all of mine (both the versions of Windows and the various linux distros) seem to be quite complete.
I have a friend who runs Ubuntu on one of his hard drives, he uses it to do his email and internet, because he's paranoid about viruses, but he still has to boot into Windows to play Lord of the Rings Online or use his scanner, etc.
I have no personal knowledge of Lord of the Rings Online, but I typed the following into a Google searchbox: linux "lord of the rings online" And I got 676,000 results. Granted, many of those results will be people asking if it can be done, how it can be done, or complaining because they don't know how to do it. But the very first result is the LOTRO Launcher for Linux. I'm not sure of this site's policy on linking other sites, but I'm sure your friend can find it via Google. Coincidentally, I have had some experience with using a scanner. I bought a new one last year. Actually it's an all-in-one device, the excellent Epson Artisan 810. Scans, copies, faxes, prints on CD/DVDs, prints screenshots from video, and also just prints. I was worried at first that I'd not be able to use it in linux or that I'd lose some functionality such as the WiFi feature (it connects via USB, ethernet, or wirelesly). But a little searching and I realized that I had nothing to worry about. I hadn't planned on purchasing a new scanner. But, you see, when I upgraded to a newer version of one of my operating systems, I was no longer able to use my old one. I'm talking about Windows here, lol.
What it all really comes down to is, it all depends on what you want to do with it.
Agreed. And also whether a person is able to easily put aside their preconceptions and unlearn previous ways that they have been doing things. And that great catch-all, personal preference. I mainly use linux. But I still use Windows on one laptop from time-to-time because of an application that I particularly like that does not run well under linux (I have found linux-based alternatives that work well, but as I mentioned, personal preference, lol). And I still use Windows on a desktop to play a few games that are annoyingly slow under linux. It's an older desktop and they're not exactly fast when playing them natively in Windows. I still buy the new Windows when they come out and I am not adverse to trying new applications that are written to run in Windows. I do not consider myself to have the "fan-boy" mentality where I wouldn't give anything but my favorite a second glance. It's just that at this time I spend 95%+ of my computer time in the linux OS. Not by conscious choice (other than the decision to try Ultimate Edition linux after several years of not using any linux OS just to see if linux had matured any; wow did it!), it's just worked out that way.