It's not even the big guys. I'm a one-dude-in-the-basement freelancer and about 5 years ago I was asked to build a device that would measure a slowly changing

It's not even the big guys. I'm a one-dude-in-the-basement freelancer and about 5 years ago I was asked to build a device that would measure a slowly changing signal and use it to modulate a 5kHz input, and generate a differential, bipolar output. Basically, read the position feedback on a machine tool and generate output that looked like a resolver. I did it half in code, half in hardware. The hardware was pricy, but it was the easiest way to get it done in low quantity. Fast forward a couple years and it's now cheap enough to do 90% of all of that in code. I could probably cut my BOM by 60%, but at low production volumes there's no compelling reason to redesign the system. So, for as long as my customer wants these, I'll build them exactly the same way.