You don't ever need to connect a laser to LightBurn to use it, but LightBurn will not run without a device profile configured, because it needs a place to store some settings, and wants to know what options to show you in the interface. If you use a laser that accepts files on a USB drive, for example, LightBurn needs to know which controller it uses so it can produce the correct output files.
Fun fact: Results show that kindergarteners tend to build higher spaghetti towers than CEOs. They typically grab the marshmallow and start prototyping right-away, focusing immediately on the end result. 153554b96e