Actual “warping” of rotors does happen but is fairly rare. It is more typical that the surface becomes uneven, often from uneven heating/cooling, and some of that can be brake pad residue left on the rotors. The hard braking will help with the residue, but the metal of the rotor itself can be uneven. This is made worse/more likely when the rotors get thinner (as in when they were machined the first time). It only takes the tiniest of imperfections to show up in the pedal or steering wheel.
Aside from all of that the simple story remains simple - you need new rotors.