It’s more complex and expensive to have it controlled by software though.

Hardware controlled would be the equivalence of using a splitter to add a second lamp on an outlet attached to a light switch. (would only require a change in a trace or two and a transistor/resistor or two.)

Software controlled is the equivalence having to buy smart outlets and programming them yourself to have the two lamps turn on at the same time. (requires the same as a hardware switch, plus a more expensive or even an extra controller chip along with the need to write and program it.)