When I go out for a hike in the woods or a hike in a new state/country that isn’t my home. I don’t go out destroying the land around me. I observe and enjoy my time
Maybe these aliens are scientists. Documenting biological life across the galaxy. Maybe they’re VanCampers. Just bouncing from planet to planet for fun
If a civilization has presumably reached FTL travel. I imagine many of their needs have been met and conquest/destruction isn’t required to maintain their supremacy. Lots of empty planets with plenty of resources out there!
Not saying aliens/UFOs are real, but I think it’s very easy to imagine them existing and not being destructive. Or maybe they’re just scouting before the invasion :)