It actually has improved a lot in the past 15 years. The problem is two fault: Enshittification/price hikes and software. Software because people still use Windows, so you don't feel the improvements. And enshittification in multiple forms like you get less for more money, Raspberry Pi is a good example of that. You are better of with other brands today like BananaPi or just a mini-PC, if you are looking for a small device with some decent specs.

Of course now we also have AI, which made it like 30x worse for every consumer, its not just GPUs or memory, its CPU, nvme storage, .. basically everything... So I really hope this AI bubble burst sooner than later now.