every airline I have flown with I would agree that the FO's are probably as qualified as the captain
In today's real world both pilots are equally qualified to fly the aeroplane the main difference being that one has to sign the paperwork.
Give me strength.
Two pilots with exactly the same licenses can, in my forty-ish years of experience (30 in airlines, 28 as Captain), range from the superb in all respects to the downright incompetent.
Airlines want bums in seats. The right-hand seat ('co-pilot' to many SLF), in my experience, is occupied by anyone with the required license. Competence ranges from excellent to minimum permissable (and below, occasionally).
Ditto the left-hand seat ('the Captain' or 'the pilot'(?) to many SLF), with the added condition that they've demonstrated sufficient ability, experience and judgement to fly from A to B without frightening or killing everyone. The standard rises from that very low base all the way up to the best aviators in the world.
...and every one of the above could hold precisely the same set of licenses.
Put three incompetents or minimum-standard morons in the same cockpit, throw in a few problems that should easily be managed, add a couple of stupid sidesticks and what do you get? You get AF447 (and there'll be more like it, you can bet on that; the 'authorities' are clueless and the airlines and manufacturers are ruled by the bean-counters).