Vilters, If I had to stab an an answer, it would be that the vane is a better instrument, in all that means in science. The output is infinitely variable, and, at least until it reaches an analogue to digital black box, fairly hard to corrupt. Okay, so why the more modern detection?
It would probably have a lot to do with the bearings and cogs technology being unsuitable for frequent high g forces. Once we get into the realms of 9 g, gut feeling is, it becomes an entirely unsuitable mechanism.