Discs solve my issue because 40mm deep is enough to not suffer from terrible crosswinds, if the wheels are made well.

The worst problem is after a few minutes of constant breaking, which you have to do if you're descending a mountain carefully and care for your life, the rim brakes on carbon start to squeal and you lose a lot of braking power. You also used to risk delamination but that isn't that big of an issue on the newer wheels.