Tyre degradation underthe influence of dirty air

[kishan.kdp]

I was wondering that while following under dirty air, downforce is reduced, as a consequence cornering speed will also be reduced. As this speed reduces since cornering forces are less, tyre degradation should also decrease accordingly, why is this not the case.
For the reason of sliding, driver will be pushing the car up to the extent it won't spin. So for the clean air sliding will also increase at a higher speed as compared to the car cornering in dirty air.
So what is the phenomenon of tyre degradation in accordance with dirty/clean air?

[Jersey Tom]

I was wondering that while following under dirty air, downforce is reduced, as a consequence cornering speed will also be reduced. As this speed reduces since cornering forces are less, tyre degradation should also decrease accordingly, why is this not the case.

Keep in mind that when you're in dirty air you're right behind someone, probably trying to attack them for position and using up your tires in the process.

[Kiril Varbanov]

Not really a phenomenon, but rather a short-lived effect, which actually doesn't have large effect on tire degradation per se, as it happens for some short span of time (unfortunately. Wouldn't we love more close wheel-to-wheel battles and some chasing?).
The effect of trying to keep the car's front end stable is much more dominant in that situation.