We have a cat who likes to chew wires. My husband, whose desk was in an area the cat hangs out in, replaced his keyboard and mouse with wireless set after losing several wired sets to the cat.
The can also be good if you have a tight or awkward space, and don’t want wires in the way. Or if you have a laptop without a lot of USB connections, and you can attach both the mouse and they keyboard via one dongle, and not need a separate cord for each. (Yes, new laptops can be short on USB ports.)