I'm not saying the triple is hard to get, It's incredibly easy to get it, actually.
I'm saying that Respite is probably not good enough to be worth spending a triple on when you could use it to do things like activate a model out of turn so you can weaken an enemy AND finish it off with your next model before it can get away, or just, like, activate Pounce on the Prowler and cause automatic wounds before you've even attacked.
I mean, assuming you both have equal triples, (e.g. value 4), and are in melee, because otherwise you're less likely to have taken those wounds (yes shooting teams exist, but the majority of the game is played in melee).
You use an action to fall back, becaause respite is not usable within 1" of an enemy, then activate respite to heal for 4, and do literally whatever else with your next action.
Your opponent uses their triple to activate Pounce, moves back into melee, automatically causing 4 wounds, putting you back where you were, and then attacks for even more damage.
Sure, you could maybe have fallen back, used respite, and then used the remaining action to move even further away, placing you outside of pounce + attack range, but then you're most likely abandoning whatever caused you to be there in the first place (e.g. an objective marker), giving the enemy the points for that round.
(Also, there's a twist card that's just "players can't activate Respite". But that is a rare occasion, giving the size of the Twist deck. Can still happen though.)
Yes, I know the probabilities. I've done a lot of math to see which models could fight which other models or when they should use which weapon.
Saying you're expected to crit more than your opponent comes back to "roll 6 to win". If you're both equally good players, but you just roll whatever you need, and he doesn't, you'll win regardless of if you're playing Warcry or Kill Team or Monopoly.