90/10 isn't even close. Typically the best and worst teams are about 2.0s apart, whilst the biggest gaps between teammates are about 0.6s. That alone implies about a 23/77 split, but it's an under-estimate of the difference between drivers because the different between teams is swollen by the fact that the best drivers get to the best teams, while the gaps between teammates are shrunk by the same. On top of that you have the massive filter on the drivers who are even good enough to make it to the grid. F1 is about 40/60 driver/car, but it only manages that because it skims the cream off the top of the best drivers in the world. Even utter potato Mazepin from last season was good enough to win races in F2; something that puts him among an elite few worldwide.