Is there any trick, workaround or maybe new way in Qt6 to create drop shadow around some component?
As you noticed yourself,
Qt Graphical Effects is removed (definitely):
The following modules are removed and not planned to be developed
- Qt Graphical Effects
Qt Graphical Effects is made compatible with the new
QRhi (Qt Rendering Hardware Interface) used by Qt6. 
Note that this doesn’t mean it will be included in Qt 6 at a later stage. 
Nevertheless, I expect it would be relatively easy to use
DropShadow from the dev or Qt 5.15 branch of git.
Answered By – m7913d
Answer Checked By – Timothy Miller (BugsFixing Admin)