When the PC is obsolete, how will you do this, and this, and this?

Last week, the PC industry was rocked by news that Q1 computer shipments had declined by as much as 14 percent, year on year. Analysts cite various factors, but they put most of the blame on a consumer shift toward tablets and other mobile devices.

At PCWorld, we wonder how humankind would survive on tablets alone. Tablets are great for casual Web browsing and catching up on email, but can they deliver everything we need in the so-called post-PC era?

Before you answer, walk with me through a tour of the PC’s greatest talents. These are the benefits you’ll give up when your last PC dies and you decide you can get by without a replacement.

There’s a reason why Angry Birds is considered the quintessential tablet game: Because most tablets can’t play real games with intense 3D graphics, demanding physics engines, hordes of onscreen players, and all the other design elements that depend on desktop-class CPUs and discrete graphics cards.

Next-generation Haswell tablets will deliver a stronger PC gaming experience, but don’t expect to play Crysis 3 at its highest settings. And good luck using gesture controls alone to play any desktop game.

Tablets are one-screen ponies. Sure, you can use a tablet as an external monitor for your PC. But (except with Windows 8 tablets) you can’t attach an external monitor to your hardware, and run your tablet OS and apps across multiple displays.

iOS and Android tablets offer varying levels of behind-the-scenes multitasking, but you can’t run multiple apps side-by-side-by-side. Windows 8 tablets address this issue with the system’s Snap view feature, but even then you can’t have more than two apps onscreen at the same time. Who in the world can work this way?

If I’m to get any work done at all, I need quick, single-screen access to Chrome, Internet Explorer, Photoshop, Stickies, HipChat, sundry Gchat windows, and even Microsoft Word.

Take a look at that iPad. Do you see a USB port? Now check out your Android or Windows 8 tablet. You might find just one. Sure, Bluetooth offers external device connectivity, but it’s not bulletproof. Nothing beats multiple USB ports when you need to attach a mouse, keyboard, game controller, external hard drive, thumb drive, and Skype headset.

Do not step to me with iMovie, iPhoto, GarageBand or Android Movie Studio. For serious video, image or audio editing, you need a full arsenal of features, along with all the precision control that real applications provide. We’re talking Photoshop, Final Cut, Pro Tools, and a host of other content creation suites. These are the applications that separate amateurs from auteurs.

Here’s a challenge: Grab your tablet, and write anything longer than 200 words on your virtual, on-screen keyboard. No? Not interested? Okay, let’s make it easier: Write anything longer than 1000 words on a mobile Bluetooth keyboard. Still not interested? No, of course not. Long-form text entry requires a no-excuses keyboard, and that means a laptop layout at the very least, and a full-width desktop keyboard if possible.

Spreadsheet work is already soul-crushing enough. Do you really want to make it worse by struggling with data entry and formulas on a touchscreen display?

Even if your tablet comes with 128GB of native storage and a slot for a 256GB expansion card, you’re looking at far less than 384GB of storage after you account for the footprint of your OS and native apps. This is not civilized living.

PCs take a bold, defiant stand against our disposable consumer culture. Components that fail can be replaced. Parts that can’t keep up with the latest applications can be swapped out in favor of better performers. Even laptops can be upgraded to varying degrees. But tablets? Not so much. Even if you could penetrate their hermetically sealed shells, you wouldn’t be able to upgrade or replace any of their components without herculean hacking efforts.

Desktop PCs (and quite a few desktop-replacement laptops) aren’t very portable, but this can be a net positive, as they rarely go places where they can easily be broken or stolen. Tablet screens shatter so often because users toss tablets around with relative abandon. And tablets get stolen in public because they’re relatively light—and concealable once the hardware has been lifted. Sure, a thief could grab your Alienware gaming laptop from your table at Starbucks, but I’d like to see him sprint down the street carrying that 12-pound computer.

Tablets are great for scanning Twitter, cruising through Facebook, and even posting short updates to either service. But if your job (or—gasp—lifestyle) depends on consuming and posting massive amounts of social media, you’ll need a real computer for the job. Throw in Google+, LinkedIn, and Pinterest, and a desktop PC becomes de rigueur.

You can’t take your PC with you wherever you may stroll, hike, or wander—but this isn’t necessarily a bad thing. Sure, your PC tethers you to a desk, but it also allows you to leave technology behind when it’s time for socializing—or a period of quiet contemplation.

Think about that the next time you’re enjoying a day at the beach, and some D-bag starts playing Angry Birds on the spot right next to you. Those squawking, chirping, tweeting birds have never been more annoying, have they?

Speaking of stuff your tablet won’t do, check out the 10 most awesome-looking and important graphics cards in the history of the PC.

Click here to check out these bad boys in all their glory.