There are two failure modes. It can also stick. I've only experience a stuck throttle cable, not a snapped one.
If it was better you would see it in motor sport.
Not at all comparable. Motorsports does not need to optimize for longevity or ease of maintenance over the decades. Both factors are irrelevant to race cars.
A highly complex interconnected message bus has hundreds of bugs (guaranteed) and many unpredictable failure modes. Also diagnostics is potentially impossible if the manufacturer hides the details.
Simpler is always better.