So my situation is: I want to place objects in a room, and I want to save their location to a file and load these later back in and have the same position. So what I do is, I have an image I track and use as the origin point to place these objects.

According to the documentation, using an anchor should improve the results. But I tried it and doesn't seem to do anything. (as in, having the objects attached to the tracked image seems to be the same as having them attached to an anchor attached to the tracked image)

I have read all the documentation about anchors (as well as a bunch of related questions and answers here), but I still don't understand them.

I don't understand what they actually do, the documentation claims they keep an object more precisely positioned in world space, but I don't understand how that can be when you always need to attach them to a trackable, seeing as the trackable is the thing that tries to keeps it in place.

So can anyone explain how an anchor is supposed to help?

I have already read this, but it didn't help me one bit: ARCore – What is the role of Anchors when they are attached to Trackable?

EDIT:

I tried a different approach: Instead of having all objects parented to the tracker, I gave all objects an anchor and did not parent them to anything. Just for testing. But this causes the objects to jump to (0,0,0) (or at least I think so), I assume because the tracker isn't parented to a trackable. (Is that true?)

But I really don't get what use they have then? What does an anchors do? Nothing at all it seems? Can anyone tell me?