Hey,
Well if pressing a button translates to full bending of the finger, even just having two stages of finger bending tracked as in stage 1 is half a bend and stage 2 is a full bend it is still more immersive than pressing a button to track in stages and we know that Leap motion is ofc capable of tracking in more stages than that.
Also after the Orion update Leap motion finger tracking is now on a Whole new level right now; Please check this video that I came across, our dear Greg: https://youtu.be/7HnfG0a6Gfg