no, we are all here for a reason, throughout our entire lives will be of some type of example to someone, and whether good or bad it will be an influence that hopefully drives an idividual/witness to accomplish a great deed, invent a better lightbulb, find a cure for cancer ect. ect., I can't tell you how many times I've heard someone talk about a dead person and say how much their lives were influenced or made better by just knowing and interacting with them no matter how long or short of time they knew them,
as for length of life, you only live for as long a time as you were alloted, when your numbers called your times up, you've served whatever purpose in this life you were supposed to, you might not think that anything was accomplished, but your time here whether seconds long or centuries influenced someone that witnessed your life somehow[what].