Your claim is essentially "Most people will never need today's high-end chips, let alone anything more powerful." This could have been equally well said in 1998. How do you know you're not as wrong making that claim now, as you would have been making that claim then? What's different?
Today's computers are powerful enough to comfortably run today's software. Tomorrow's computers will have a lot more power than today's software needs; but that's irrelevant, because they'll be running tomorrow's software instead.
To lay out my case in a little more detail:
"As hardware resources increase, software will bloat until it consumes them all." This is probably somebody's law, but I don't know who off the top of my head.
You don't really need more than ~300 MHz, 128 MB to do what the vast majority of users do: Word processing, email, and displaying web pages.
Usage patterns may change as you increase the amount of computing power you need. For example, I usually have a large number of tabs open in my web browser -- I probably wouldn't use the browser in this way if I had much less memory.
Some software is just bloated. My Windows box has dozens of different auto-updaters that run on every boot. Steam does literally hundreds of megabytes of I/O doing -- something, Turing only knows what.
Of course all the latest UI's have all kinds of resource-intensive 3D effects, run at unnecessarily high resolutions, use antialiased path rendering for fonts instead of good old-fashioned bit blitting, et cetera.
The point is that, as the standard hardware increases, OS'es and applications will add marginally useful features to take advantage of it. Users will learn new usage patterns that are marginally more productive but require much better hardware. As standard software's minimum requirements rise, people buy new hardware to keep up.
This is not a novel idea; it's been the story of computing for decades, and a trend that anyone who's been paying any attention at all to this industry has surely noticed.