Critical Hit and Direct Hit are strong stats by themselves because of how they interact. Det is a jack of all trades stat, never bad to have a good amount but also not the best to focus. What makes Critical and Direct to be valued together is how they combo with eachother while the game provides a vast quantity constant of buffs to those rates via Litany, Stratagem, Bard songs, Battle Voice and they all stack together. The more of those you have thne beter Critical Hit becomes. That's why people value those stats and jobs that provide these buffs altogether.
In average D Hit is strong by itself. When stecking many Critical buffs Critical becomes very powerful and values your Direct even more. Each point in D Hit ramps you rate to D Crit more than each Crit point but Crit points make the big flashy D Crit to ramp up its multiplier. Outside these two, Determination is a nice stat that is never useless, but won't be the strongest either. Critical and D. Critical hit can possibly let you hit higher damage potentials as well when it happens in specific points of certain job's rotations, in MCH specifically those points are Wildfire windows.