New Magic Mouse and Keyboard Fail to Work with Older macOS Versions

Apple's new USB-C Magic Keyboard and Magic Mouse are failing to work with versions of macOS before 15.1, or with the current beta of 15.2. Despite Apple listing compatible Macs as old as 2018, users must update to macOS Sequoia 15.1 for full functionality. The peripherals have switched from Lightning to USB-C connection, but it's not clear why there should be issues with wireless connectivity. Reports appear to exclusively discuss the wireless connection problems with macOS and not iPads.