the first officer on a commercial passenger jet holds the same licence and is equally well qualified to fly the aircraft as the captain
Define 'equally'? First Officer limits are more restrictive for crosswinds, takeoffs in fog more restrictive. Approaches into various airports more restrictive (Chambery for one, LCY as well as Innsbruck), and Cat 2 and 3 approaches are Captain PF. Such restrictions are not a personal insult, but the copilot has to develop his skills and experience, so it's not really a case of 'anything a captain can do, a copilot can do'!