Hi, in Big Sur, dragging a file from the Desktop (as an example) to a folder on the Desktop results in a move operation. To only copy, use the option key while dragging. You can also undo either the move or copy by pressing the Command key.
You said you don't want to hold down the key, you can choose to use a smart right-click tool iBoysoft MagicMenu. Free download and install it, then right-click the files you want to move and click "Move to" to select a directory.
Also read: How to Cut and Paste on Your Mac?