A common misconception is a router lasts forever. It is electronic, no moving parts, why should I upgrade?
Ten years ago, we would agree. Basic WiFi was all that was needed, and a household had maybe 3 devices on WiFi. People had a single desktop wired up to the router. We see 7-10-year-old routers that will do at most 25Mbs, and are sensitive to interference which creates high latency or even periodic disconnections.
Today, average homes with 4 people have over 30 devices. Smartphones, laptops, tablets, NEST thermostats, Amazon Alexa, Chromecast, smart watches, gaming consoles, smart TV, printers, cameras, and even robot vacuums.
The increase in the number of WiFi devices creates more challenges, but especially the need to have WiFi in every corner of your home, including the basement or 2nd floor, maybe even in the garage. And then there is the newer 802.11ac standard using 5GHz.
Many routers have “repeaters” which will help propagate the signal from your main router location. A great feature is the ability to add a second network of “guest” and leave it posted where visitors can see it and easily connect. Most newer cell phones have 5GHz – but this is different from the newest 5G cellular services you may read about.