It is possible.
Simplest way, you can use a Click activity and in the CursorPosition set Position to TopLeft and use OffsetX and OffsetY to input the coordinates.
Using Hover activity at first might be good, to not click on random things if you’re off.
To get the coordinates, start with the Indicate On Screen and hover over what you want to click (see the preview window).
Make sure you put the activities inside AttachWindow/Browser and that the window is top most, to not click on something else that’s on screen.
This is not recordable though, you need to do it inside the activities, not through the recorder.
Aside of that, I haven’t encountered something that a good selector would not be possible to build, especially if the application itself is static enough to be operatable by coordinates (even idx selectors should be relatively safe in that case).