Why did Trunks not just kill Dr. Gero?
After years of not wanting to dive into dragon ball my friends (who all but one have grown up with) begged me to watch/read and got me to cave in. I was wrong, and am thoroughly enjoying it. Just got to the beginning of what I believe to be the android arc, where trunks comes to the past for the first time. Why didn’t Trunks just kill Dr Gero? What about the rest of earths defenders, why don’t they just track down the Dr. before he makes the androids? If the answers to these questions are answered later then try to be as vague as possible, thanks.