If someone very short or otherwise unable asks me to get something not over-heavy/awkward or otherwise dangerous to get down ....and they ask *politely* I really don't mind putting my height to use. I would object to being barked at or ordered around. As it is, generally speaking an "Excuse me but could you reach the pudding mix for me dear" has never failed for the many folk who've asked me nicely.
I'm not that tall, but have helped out others who are shorter than I am. My issue is with short arms. I once had to ask a worker in target if he could please reach the yogurt that was waaaay back on the top shelf for me. But I said please and thank you, just like my mom taught me
And another time, at trader joes, I wanted to know if they had any more jam which was on the bottom shelf, but not visible. due to bad knees and back, I was unable to crouch down, and so i asked one of the guys working there if he could look for me. I felt terrible that he actually lay down on the floor (only way to see if any were on the very back of the shelf) but as I said to him, there was no way if i got down, i'd be able to get back up!