"Iirc, Apollo era fault detection, and probably Soyuz too, consists of a long piece of wire"
Actually it was a bit more complex, as described here
The trick is to not identify fault patterns, then install sensors to find them (which need wiring and processing, and might themselves be faulty), but find the signatures they cause
Mostly viciously aggressive acceleration. The cause don't matter, just the results.
Apollo also put the 'nauts in the loop to track slower developing possible problems (which might get bad enough to go to a full abort, but might just as easily decay back to nothing).
It would seem a large part of the EDS was in fact hard wired, using diodes and (gasp) relay logic.
Note that the basic trajectory to orbit (and how fast it's traversed) hasn't actually changed in the 5 decades since Apollo.