Maybe a tent isnt a good example. There is a good chance the owner is somewhere around. Same thing for a backpack. But sometime your guess can lean to one side or another. If the pack is zipped up and lying against a rock, maybe the owner is somewhere behind a bush answering nature's call. But a backpack that is open an half empty .. and just lying somewhere near the trail....

Lets say what you found is a small item that is in no way left there on purpose like a knife, a hatchet, a first aid kit. And then suppose it is expensive like a customized knife( to make it worse for your conscious LOL).