Question

What is the cause of friction
is it because of the irregularities in the surfaces or because of some electrostatic forces?

Answer 1

Actually, every object outer layer is not fine, when we rub two object , outer layer of objects meet with each other and fitted like a zig-saw. This oppose the motion. As, this is only possible in solid.

In water and gas , molecule collide with each other and oppose motion.

Special case : Greater the rough surface , greater the friction

But this is not apply on all object , there are also other factors which affect friction,

Like two plane glass , stuck with high friction as they are not rough surface

cause of friction is attraction between molecules near the surface of the objects. What you describe is electrostatic induction. This could be the source of the attractive force in some cases.