Yet none of these new model cars re-arrange the pedals. They'll change the style of the brake lights, the trim, etc, but the basic "4 wheels, front two steer, wheel turns towards the direction you want to steer, brake, gas pedal" is fixed. But with software (including Firefox) even the operational aspects change, not just the cosmetics.

Even more: with software, everything can and does change overnight.

As if some pervert burgles your garage and does not go stealing, but replacing your car.

But the basic way you navigate the web doesn't change much either; there's still the address bar, back button, and html and JavaScript.

And you're underrepresenting how much change can happen for a given model: over decades the Honda Civic has gone from manual to continuously variable transmission, and entirely different chassis, etc. as technology and safety expectations evolve, and it's no exception.