There are actually technologies that were refined to such a high level, that they're not improving over time. Analog technology reached it's zenith years ago, and most of what goes on now with development is more along the lines of tweaks, new flavors, and workflow features.
Microphone technology has not improved in over 50 years. But it's gotten less expensive in many cases. It's easier for designers and manufacturers to source parts. It's also easy to get the word on with the internet, so we've had more and more companies jump on the bandwagon.
Some of the newer materials used in speaker drivers are not necessarily an advancement. It's just something different. And for many, those differences aren't a positive. Good ol' pulp paper cones are still preferred by many, who feel that synthetic materials in cones slow down the responsiveness. This is true of even very high-end speakers.
In many cases DSP is incorporated to solve problems that were not solved in the analog design of the monitor. And also DPS if often more of a gimmick, and doesn't really solve any problems, or even actually legitimately provide the results claimed.
More often than not, a purist approach is still what produces the best monitors and microphones. And one are where that's been helped by tech advancement is the ability for manufacturers to use computers and software measurement programs to more accurate refine and produce their products.
I wrote an article on some of the history of accurate reference monitors, which also addresses the use of materials.
The Danish Connection: The Rise of Accurate Reference Speakers and Monitors - Dan Richards