Gemma, my comments on motorcycling were based on the 1970s and the early 1980s, when there were far fewer cars (about 3x fewer) on the UK roads, and very few half blind OAPs were getting tax free lump sums from private pensions with which to buy cars
Surveys at the time showed 2/3 of accidents (involving a car and a bike) were caused directly by the car driver, usually by pulling out of a side road or similar. I am sure it would be worse now, but maybe not due to stricter medical reuirements. The biker cannot do much about those risks.
Also there were many times more bikers back then - many young people could not afford a car so had a motorbike. Today's bike accident figures are hugely skewed (for the better) by a much reduced biker population.
The risk profile in flying is completely different. You could fly around blindfolded for the rest of your life, 24hrs/day, and would prob99 die of natural causes before hitting something airborne. Fly above 2000ft and the UK mid-air risk is no longer supported by any data at all. Look after the plane, engine especially, and the numbers get even better.
When I had to do the Lyco SB569 crank swap, I sent it to a highly regarded specialist engine shop in the USA. Too many horror stories of UK rebuilds causing various failures. And the U.S. job cost $12k plus shipping, which is a lot less than any of the UK outfits. One now-defunct outfit quoted £10k for the same work and my 'due diligence' found about 50% of ex customers wouldn't touch them again.