You can now tap to nudge blocks across the grid with arrow keys, quickly moving them up, down, left or right. Pressing the arrow keys while holding the shift key will nudge the block by 10 columns instead of 1, making it easier to move blocks across the grid quickly.
These keys will not nudge blocks when you have text selected in a text block, these are resered for navigating inside your text content.
So, there's always drag and drop available when you start dragging any block across the grid in desktop or mobile.