I've felt this way since I built my last desktop in 2008. I was sort-of waiting for the "gee its time to upgrade" mark to roll around in 3 or 4 years, but it hasn't happened yet. Any games I want to play it still runs very well, and it still feels very fast to me even compared to modern off-the-shelf systems. When my friends ask for laptop-buying advice I tell them if they like the keyboard and screen, then its just…
At the same time, I think even the "average" person would want more than a 128gb ssd, and therefore today's entry-level harddrives equipped with these small ssd's won't age that well. I know, I know, ssd's come in larger sizes --- but they become significantly more expensive, and most entry-level notebooks (with ssd's) come with 128gb. As a comparison, it's almost weird that years ago you could get a 500gb harddrive without giving it a second financial thought. As such, I think that if there is anything that a normal person might want, it's more harddrive space as they fill up their small-ish SSDs --- so that they don't need to worry about deleting things when they have too many pictures, games, etc. The average person won't want chrome to take half the number of milliseconds to open a new tab, or their games to go from 40 fps to 60fps. But, to me it seems easy to fill up these smaller harddrives, and many people might be looking for a new computer to deal with that.
Before someone mentions it: YES, cloud solutions and external solutions exist. But is it part of mainstream usage to store your stuff on an external hdd? Also, wouldn't people anyway want a future computer where they didn't need to do that? I'm not claiming they have terabytes of data, but I think over the course of 3-4 years, people could pretty easily accumulate > 256gb of data. Otherwise, is there a free and easy cloud solution that gives > 50gb of space that people use a lot today? (Not to my knowledge)