I know of only one real world successful product using analog computation in place of expensive high end micro. It was the first proper (no dedicated special mousepads) Optical Mouse designed and build by HP->Agilent->Avago and released by Microsoft in 1999 as IntelliMouse Optical. https://gizmodo.com/20-years-ago-microsoft-changed-how-we-mo... Afaik Microsoft bought 1 year explosivity for the sensor. Avago HDNS-2000 chip did all the heavy lifting in analog domain.
Travis Blalock Oral History https://www.youtube.com/watch?v=wmqa9XJED-Q https://archive.computerhistory.org/resources/access/text/20...:
"each array element had nearest neighbor connectivity so you would calculate nine correlations, an autocorrelation and eight cross-correlations, with each of your eight nearest neighbors, the diagonals and the perpendicular, and then you could interpolate in correlation space where the best fit was."
"And the reason we did difference squared instead of multiplication is because in the analog domain I could implement a difference-squared circuit with six transistors and so I was like “Okay, six transistors. I can’t do multiplication that cheaply so sold, difference squared, that’s how we’re going to do it.”
"little chip running in the 0.8 micron CMOS could do the equivalent operations per second to 1-1/2 giga operations per second and it was doing this for under 200 milliwatts, nothing you could have approached at that time in the digital domain."
Extra Oral History with inventor of the sensor Gary Gordon: https://www.youtube.com/watch?v=TxxoWhCzIeU
The optical mouse is great example. There are lots pre-90s ofc such as in military applications.
One of the reasons for failure to compete is that actually all computers are physical computers. Therefore digital is still tethered to one of the greatest analog components ever discovered and as a result when you do analog ai you are really competing with the physics of the transistor. The digital computation is the complex icing on the top of an analog cake.