Keyboard or touchpad shortcut to move windows between screens?
Solution 1:
There's nothing built in, but there are third-party programs that provide this functionality. I use the free open source Rectangle which provides shortcuts ctrl-opt-cmd-→ to move to the next display to the right and ctrl-opt-cmd-← to move to the next display to the left. It also provides shortcuts for other positioning of windows (e.g., left/right third/half/two-thirds, top, bottom, etc.).