This is true but most of the ISPs I worked with (in an admittedly smallish town) would often upgrade for the user every 5 years or so. A lot of the times it was needed as they shipped the cheapest routers they could get, even when it wasn’t they’d roll out new stuff as people called in. 10 years I could see, my mom and dad used the same tiny netgear modem/router for 7 before having me redo their network.

This is true but I think, ime at least, most people don’t buy their own routers and get a cheap modem/router/Wi-Fi ap unit that gets replaced every few years when they experience issues. Then again my experience was It so it wasn’t like the people who never had issues called.