roflwaffles
Member
They only went to the future once without a plan and that was because Beerus assured them that he changed the future by killing Present Zamasu. So it wasn't 'bad writing' since the show explained why it happened.
They went to the future to check if the future changed. They had zero plan on what to do if it hadn't. Trunks was skeptical that it would have changed since thats not how time works in this universe and he knows first hand.
It's bad writing. Goku might be a complete moron, but Vegeta and Trunks know well enough that they're likely to get destroyed by Black if Beerus likely isn't right.