> there is no stuff like drag and drop between screens.

"It is even possible to drag the current screen down to reveal another screen behind it, (even if they have different display resolutions) so that you can view two screens simultaneously, or even drag and drop files and other content from one screen to another.
https://en.wikipedia.org/wiki/AmigaOS_4#Appearance

> screen dragging [...] was not implemented on purpose.

It may have been a welcome byproduct on the old OCS/ECS/AGA chipsets, but on OS3/CGX, OS4 and AROS it has been implemented on purpose.