So here's the argument i'm seeing, end game players don't want non end game players to be wearing end game gear.
Yet the crafters are the ones that still can make the "Best" gear in the game. So what's the point of end game content, if some crafter can make something better? There isn't even a need to complete the end game content to acquire it.

My suggestion makes the endgame content worth doing, as for others acquiring the gear or drops that comes down to greed of end game players who sell it to others. The other option, would be to do something like cursed gear in 11, where an NPC combines the crafted and dropped but if a crafter can still make a better piece, I still see it as pointless to do anything other than make as much gil as I can and buy what I want.