Probably not, but they’re nice to have. Speeds of 1,000Mbps and higher will support a large household with numerous connected devices, but so will speeds of 500Mbps or possibly even 300Mbps. The appeal to gigabit service is that it typically doesn’t cost much more than a 300 or 500Mbps plan, and the speeds will all but guarantee you’ll have enough to go around for every connected device.