The reasoning laid out in the article boils down to: Analog doesn't compose.
There is no fundamental element in the real world that you can combine to build arbitrary analog circuits, while you can do just that with digital circuits.
Related Veritasium Video: https://www.youtube.com/watch?v=GVsUOuSjvcg Future Computers Will Be Radically Different
https://analogparadigm.com/ looks promising.
Universal analog chips are cool, but extremely expensive, and their analog performance is moderate.
- Their analog performance is enough for simple hobbyists projects, but for commercial, need something with much more precision - 18 bit or more.
That's what differ analog computers from digital - in analog easy achievable ~ 10-12 bits, but more are expensive;
in digital, could trade precision for speed - for example calculate 64 bit on 32 bit hardware, which is at least 4 times slower (in ideal cases, in real more than 4x difference), but double precision worth it.
Even more, in digital world, could calculate 32bit or even 64bit on 8bit hardware (really used in microcontroller world), which is extremely slow, but for many cases is fast enough.
The biggest problem is that analog is nothing like digital - BTW my PhD thesis back in the 1980s was about this. You can make it work at low frequencies that are essentially "DC". Higher frequencies simply can't work - too many parasitics plus lumped equivalent fails.
formerly_proven hits the nail on the head.
Cypress PSocs [1] were super fun to use. Visually interconnecting PWM, ADC, DAC, OpAmp/comparator blocks and then accessing the "pins" in C code... It's like Arduino but you get to also compose the analog side. Back then it was an 24 MHz 8-bit controller, now it looks like they have some muscle in them.
PSOCs are very useful for things that interface with the world -- for example, they were used in the iPod touch wheel ... I've used them to make:
* hearing research devices (some filters in the analog side of the device)
* wearable DJ system (MIDI, ADC/DAC for controls, some PWM, some analog synth, capacitive sensing)
* smart sex toys (ADC/DAC/PWM, some filtering, capacitive sensing)
[1] https://en.wikipedia.org/wiki/Cypress_PSoC