Legacy ports
Your older Mac is likely to have ports that your current favourite computer lacks. FireWire ports, for example, haven’t been used in a Mac since 2016. Do you have a FireWire drive you’d like to use for archiving, or a FireWire iPod gathering dust like your old Mac was? Get ‘em out. Your older Mac will have old-school USB-A ports too, so can use peripherals that need this connector without having to use adaptors or hubs.