I think this is how giants fall. The various titans of times long gone - steel, chemical companies, mines etc. were one day so mighty that it was impossible to

I think this is how giants fall. The various titans of times long gone - steel, chemical companies, mines etc. were one day so mighty that it was impossible to imagine them faltering. And then they stumbled, then tripped, then eventually fell. Google, Facebook, Amazon will probably all eventually be replaced by a plucky, energetic and hungry competitor out of nowhere, just as they exploded in the faces of the predecessors.