What’s the point of training legs if you don’t need to run, jump, deadlift or squat to survive or to be happy?
Hell, why train any body part?
I know some very healthy, happy people who only do different types of cardio to keep their heart healthy, and I don’t think they ever needed more muscle to live happily.
Saying you need leg strength to do anything is just like saying you need benching strength to push that object off of you in the slight chance you run into that scenario, in that position.
When was the last time you really needed to jump real high, or use all your might to squat something a few feet?
Oh, and I have used a pressing motion when I moved from one house to another. Squeezing between a Uhaul truck wall and pile of furniture to make some extra space, where if I had to take everything off of the pile to move it, it would have taken me a lot longer, and used a lot more energy.