Dial-Up Modem
Since the invention of the wireless router, dial-up Internet has become totally useless. It's slow and usually only allows one person to be online at a time. Now, with the use of things like the Xfinity app, you can set up and control your Wifi remotely.
Floppy Disk
Unless your computer was built 40 years ago, you don't need to use floppy disks. They used to hold games, software, and important programs, but now they're just chunky pieces of plastic that don't serve any purpose. Now, most software is downloadable, negating the need for any physical disks at all.