How is wake-on-LAN patentable? It's literally just "send signal to device that flips a switch". Can each application of basic remote-control be considered a new

How is wake-on-LAN patentable? It's literally just "send signal to device that flips a switch". Can each application of basic remote-control be considered a new "invention"? These patents aren't about overcoming technical challenges, but about just the idea of doing something. It's like getting a patent on the idea of converting heat to work, then suing everyone that makes a heat engine of any sort.