While Wi-Fi is more popular and prevalent than ever, it's still no match for a hardwired ethernet connection. But many of the new routers, especially mesh routers, don't have many ethernet ports built into them. Fortunately, if you have at least one ethernet port, you can expand that to as many as you need with a "Switch". Netgear makes some quality switches, but any unmanaged networking switch should work just fine. They all are very easy to use, as long as you get an unmanaged Switch. All you need to do is plug the Switch into a spare ethernet port on your router, and you'll have more ports for plugging in other devices that you want on your network.
One such device that's great to have on your network is a NAS (Network Attached Storage). Leo likes Synology NAS. Then you can have all the computers on your home network automatically back up to it when they're connected. This can play a vital role in your backup strategy. Leo recommends the 3-2-1 method: 3 copies, on 2 different forms of media, with 1 copy off-site. You can learn more about that backup strategy at dpbestflow.org.
Watch Leo Laporte explain how to add more ethernet ports to your router, and set up a robust backup strategy, on The Tech Guy 1493 here.