I have a 75/6 now 400.000 km needs adjustment almost every 3500 km still runs but not the way it should). Failures: some times...
Have had a R80 mono from 86. 200.000 km broken coil (old grey one they all crack) no further problems.
Now I ride a R80 mono from 93 with 390.000 km ( replaced the coil from new) never had a failure.
R100 mono from 91 with 230.000 km ( again a new coil to avoid failure of the old grey one) never failed
R100gs owned it for a few years. Never had an ignition problem with it. Just used it in the mud. Km's ??
Personally I do trust the electronic ignition. But I still bring spares on big trips.
I have seen plenty broken ones on other bikes. Maybe I was lucky !!