As shown in the figure：
I often need to drag the corner icon to every corner of the image.
This operation is often used.
Can the Unity team add a button instead?
Those anchors are supposed to be relative to the parent object, not to the object itself. This allows that object to scale and position based on it’s parent’s shape and size. Your buttons will resize in an ugly way with those anchors if the parent object changes sizes, which often happens if you use a different-sized screen (like PC vs Mobile, or extra-wide monitors).
What are you trying to accomplish by shaping the anchors like this? Maybe I can help.