I'd say 95% of the problems in the series could've been avoided had the main characters not made idiotic decisions.
Sure Goku, I'm sure your evil brother Raditz will be a good boy and leave if you let go of his tail.
Sure Piccolo, tell Raditz about how there are magical Dragonballs on earth that can grant any wish. Not like Raditz has any of his homies on two-way.
Sure Vegeta, go ahead and try to fight Frieza. His final form is kind of puny and doesn't look all that tough.
Sure Frieza, Goku is just standing there defenseless with his hands held up in the air. Maybe you should attack him? Or at least look up? Nah, I'm sure he's not up to anything.
Sure Frieza, instead of just killing Goku, go ahead and piss him off by killing his friends and trying to kill his son. I'm sure nothing bad will happen.
Sure Goku, go ahead and let Frieza live. I'm sure he'll be a good boy - it worked so well with Raditz.
Sure Z-fighters, you just heard that two deadly androids will appear in 3 years and kill you all. Don't use the Dragonballs to find Dr. Gero and stop him before that happens, just train and assume you'll be strong enough to fight them.
Sure Vegeta, don't listen to Trunks' warnings about Androids 17 and 18. Go ahead and fight them - I'm sure you'll win since you're a super saiyan now, right?
Sure Android 18, go ahead and stand around while everyone is telling you to run away so Cell won't absorb you. Nothing bad will happen.
Sure Vegeta, help Cell reach his perfect form and stop Trunks from killing him now. It'll work out.
Sure Goku, just stand on the lookout doing nothing while Cell is trying to absorb 18. I mean, not like you have this move called Instant Transmission you could use to teleport her to another planet.
Sure Goku, give Cell a senzu bean and then send your son to fight him.
Sure Gohan, don't finish Cell off. Make him suffer. Nothing bad will happen.
Sure Goku, don't transport Cell to some uninhabited planet and then teleport back before he blows up. Take him to your homie's planet and then stick around so you all get killed.
Sure Vegeta, let Babidi use you to get energy to awaken Buu just because you caught feelings about Goku. I'm sure nothing bad will happen.
Sure Vegeta, I'm sure your suicide attack against Buu will work. It's not like he can regenerate from everything.
I could easily think of a LOT more of these too. DBZ characters in general easily win the award for fictional characters.
Sure Goku, I'm sure your evil brother Raditz will be a good boy and leave if you let go of his tail.
Sure Piccolo, tell Raditz about how there are magical Dragonballs on earth that can grant any wish. Not like Raditz has any of his homies on two-way.
Sure Vegeta, go ahead and try to fight Frieza. His final form is kind of puny and doesn't look all that tough.
Sure Frieza, Goku is just standing there defenseless with his hands held up in the air. Maybe you should attack him? Or at least look up? Nah, I'm sure he's not up to anything.
Sure Frieza, instead of just killing Goku, go ahead and piss him off by killing his friends and trying to kill his son. I'm sure nothing bad will happen.
Sure Goku, go ahead and let Frieza live. I'm sure he'll be a good boy - it worked so well with Raditz.
Sure Z-fighters, you just heard that two deadly androids will appear in 3 years and kill you all. Don't use the Dragonballs to find Dr. Gero and stop him before that happens, just train and assume you'll be strong enough to fight them.
Sure Vegeta, don't listen to Trunks' warnings about Androids 17 and 18. Go ahead and fight them - I'm sure you'll win since you're a super saiyan now, right?
Sure Android 18, go ahead and stand around while everyone is telling you to run away so Cell won't absorb you. Nothing bad will happen.
Sure Vegeta, help Cell reach his perfect form and stop Trunks from killing him now. It'll work out.
Sure Goku, just stand on the lookout doing nothing while Cell is trying to absorb 18. I mean, not like you have this move called Instant Transmission you could use to teleport her to another planet.
Sure Goku, give Cell a senzu bean and then send your son to fight him.
Sure Gohan, don't finish Cell off. Make him suffer. Nothing bad will happen.
Sure Goku, don't transport Cell to some uninhabited planet and then teleport back before he blows up. Take him to your homie's planet and then stick around so you all get killed.
Sure Vegeta, let Babidi use you to get energy to awaken Buu just because you caught feelings about Goku. I'm sure nothing bad will happen.
Sure Vegeta, I'm sure your suicide attack against Buu will work. It's not like he can regenerate from everything.
I could easily think of a LOT more of these too. DBZ characters in general easily win the award for fictional characters.