It's difficult to work out what you're trying to say here, but it looks very much as if you think tablets and smartphones are a passing trend because PCs are better for playing games on?
Sorry, but that doesn't make any sense. PC gaming is every bit as much a specialist activity as web development or video/graphics work. High-powered desktop machines are always going to have a place. But there are plenty of activities that don't require the power of a desktop machine, or the desk space or the office chair.
And I have typed all of my posts in this thread on an iPad keyboard.