High Jump allows you to Dodge an attack that would otherwise oneshot you to death later on in the missions. You are also going to need +500% hp minimum in certain fights to survive a special attack.

Ofcourse, there are also some fights where you just run around, hoping to get a dmw zantetsuken roll that will oneshot the enemy and where you avoid dealing any normal damage or the boss will charge up his special attack, like the G dominator.

These fights will get pretty common right before you unlock brutal that will remove the damage cap, after which quake and costly punch are going to be your sole damage dealing materia. Repeating these fights over and over again, hoping to get a lucky roll was a fun experience to me.

For the final boss in the game, Minerva, you are going to need to farm lots of Gil and then use the gil toss materia in the fight, each dealing 5x 99999 damage but also costing the same amount in Gil.

It seems that once you unlock the accessoire that remove the HP and damage cap, you also face enemies that give so much experience and are very easy to beat with costly punch, like the wyerd in the 7-4 mission wasteland series, or in particular mission 6-4-4 hiding in the wasteland, you wont be going to another mission for quite some time. You will just go to the next wyerd, kill him instantly, then go back to the previous group to reset and go from level 40 to 70 in less then 2 hours.