Daxos was never especially popular, the character generating more hype than the mechanics of the card, as Daxos death in the larger story had only happened about 18 months prior
Still, its played mostly because there arent any other better options (just give me Careful Study!) I play two or three copies
If youve seen some of the cards available in Modern, youll know that this gives you a disgusting amount of options, and doing it all in reaction to somebody attacking you or during their end step is rather silly
Lifegain has started to get more draw, too
Cloudshredder Sliver, Alibou, Ancient Witness, Thopter Engineer, and Karrthus, Tyrant of Jund are all excellent tribal payoffs