Would Aliens Destroy Us Or help Us?

Why do we assume that aliens would show up and annihilate us? Maybe aliens would take pitty on us and actually help us.  

Conflicts around the world:

Crisis Group International: https://www.crisisgroup.org/visual-explainers/10-conflicts-2023/

Global Conflict Tracker: https://www.cfr.org/global-conflict-tracker

Geneva Academy: https://geneva-academy.ch/galleries/today-s-armed-conflicts