Since you're referencing monk, the stat weights change job to job, and as a monk, it's generally agreed that you should be stacking as much critical hit as possible in order to get more chances to proc a chakra, same with bard and their Repertoire procs.
After that, I've not seen a clear consensus as to which stat is the winner on each job, but as was mentioned, if you pick one and stick to it, it likely won't make a massive difference between one or another. I went with direct hit as my other secondary stat on monk because I like seeing the enormous numbers on a direct critical hit, but there's the argument that skill speed might be better since more hits more often means more chakras, and potentially more hits under Riddle of Fire.