Your stats are suspect. I believe RK had 3 crashes this year, which seems not far from average (depending on who blame is assigned to). I doubt vettel, Bottas or grosjean among others did much better. Regardless RK is who he is, everyone including himself seems aware of his limitations. I wish the story would have been better for this year, as it would have been a bright spot in an otherwise uninteresting f1 season. A reserve spot is a place where he may add value to a struggling team, as a consultant or mentor to younger drivers. fwiw, I don’t think any drivers in f1 could have done much better on Williams.