Bottas has very good one lap pace, this positions him well for the race and provides coverage for Hamilton strategy. That’s almost literally the perfect teammate. He’s not as good as Hamilton but since there are probably about 10 people who have ever lived who are and none of them are active in F1 it’s hard to hold that against him.
The reason to replace is for succession planning. If Gasly proves anything it’s that it’s not just the car. Ocon being out of competitive racing for 2 years would be an enormous risk. A year alongside Hamilton allows
a handover period – knowledge transfer by virtue of racing in the same garage as one of the legends of the sport
pace validation – how good is ocon, how does that translate to race pace, is he one for the future
lower expectations since his teammate is a 6 time WDC
competitive preparation for the big rule change in 2021
Russell is available to join the team in 2021 but is effectively going to have to wait for Hamilton to hang up his gloves. I imagine Hamilton will look to go out winning in 2021.