Each new hard drive standard has required a faster motherboard to take advantage of it.
WiFi standards are backwards compatible in the sense that they work with older hardware to send at the maximum speed that those radios were capable of transmitting.
The crux of my initial comment is that it would be awesome if we could some how get around the last issue and not have to replace hardware in order to use a different frequency, which @walshemj points out is a physical impossibility, but I believe I read an article a while ago in which someone had gotten around this?
We do have Software Defined Radios, which practically allow you to tune to a much wider range of frequencies, and speak nearly any wireless protocol though.
Plus, what would they sell you next year? To be sustainable, the company would have to be mostly a software company that people are willing to pay license or upgrade fees for increased functionality or performance. There may be a niche for that, but most people won't upgrade their router or CPE for free. At scale, I doubt that would pan out, especially with increased, upfront hardware cost.