And yet, people buy SSDs even though they could get more memory in a HDD. Because they value speed over capacity.
"The Innovator's Dilemma" traces back the disk drive industry, and in each generation, people choose smaller memory capacity, for the sake of a smaller package (there used to be 8 inch drives, for example). The theoretical idea is that once users' need for performance is satisfied (it's "good enough"), they turn their attention to other issues - such as price, convenience/ease-of-use, customization etc.
It has happened with desktops: that's what caused the brief "netbook" popularity, and what made smartphones successful. Desktops had overshot what was needed for many tasks (browsing, email); but the smaller devices were just becoming powerful enough to manage. So although desktops were more powerful, that extra power didn't matter to many users.
The underlying idea is twofold: (1) all technologies improve over time, as engineers find better ways to do things (Moore's law is just one example); (2) what users demand also increases over time, but at a slower rate
Therefore, if you start with new approach that really struggles with many tasks, eventually it will become powerful enough for what users need; during the same period, the old technology started off powerful enough, and became even more powerful - but users didn't care, because it was more than they needed (or, at least, they didn't want it as much as they wanted other qualities, like convenience etc).