> Camber isn't a magical trick to get more grip; it's a way to restore grip that would otherwise have been lost because of uneven tire loading in a corner. In a straight-line drive situation, the load is already ideal; the contact patch is the maximum size and fairly evenly distributed across the width of the tire.

Mostly. But only mostly. Tire grip is actually really, really, really complex however, and this is one of the places where a simplistic model breaks down really badly. If we were able to model tires with simple newtonian physics, then no car would be able to hold more than 1g in a corner, as at that point the force sideways would be more than the force of gravity holding it to the road. Manifestly this is not actually the case.

Tire grip through a corner is more than just coefficient of friction against a surface. There's a lot of complicated things that happen, but the one I'm going to very lightly cover here is that when you go around a corner your tires deform slightly. The sidewall of the tire is pulled out of place, and at the maximum cornering speed of a tire, it will actually be slipping slightly (which can be heard as tire squeal). Cambering the tire corrects for uneven loading, but it also changes the sidewall stress profile, and thus affects the way the tire deforms under lateral load.

I found a mathematical explanation of some the bits mentioned above here: https://physics.stackexchange.com/questions/5838/why-does-a-... but I haven't checked carefully through it to ensure it's actually correct.