What is the point of layers? (2.8)

I take it i’m a noob and am not aware of something.
im using 2.8 …there are many things not yet implemented so that’s probably why.

we have collections layers and groups (groups are more for like certain types of edits)
but then groups also hold shapes, why both?
why can’t i move a group that’s only an object. like convert it. to put in new collection.
(so no need to think about making new layer when planning on adding modifiers to specific part.

or like can I copy a shape from one group? and make new layer and paste in place?

I get that collections are folders

objects are like equivalent of sketchup’s group.

layers are ? a way to make a new object outside of a current object

why not have it so
when create a layer just create a blank object canvas.
when you select it or right click it it will show a drop down of what to add to it and this appears on viewport at origin. and takes on the name of object you created.