Both pairs of limbs are crucial and important, but I think arms are marginally more important. I've spent some time in a prosthetics hospital and have seen how some people can regain mobility with lower-limb prostheses. Hands on the other hand, are way more intricate; fingers especially, have the third most sensitive tips in our bodies after our tongues and genitals. The range of intricate movements carried out by fingers are also yet to be achieved by anything out there. Writing, typing, lifting, grabbing delicately, holding firmly, temperature sensitivity, e.t.c, e.t.c, make the hands irreplaceable I think.
I hope and pray to never have to chose, but I feel as though a person in a wheel chair with the use of their arms and hands is marginally better off than someone who can walk but cant use their arms/legs.
You must have seen quiet a few and your experience made it obvious and easy to choose hands over legs.
Like you said, may we not have reasons to choose because they are both vital