Some phones and best camera ones have good enough sensors capabilities for many, but their phone size doesn't fit a full frame sensor by a long shot, so a camera for, say, 2-3k (sure, 2k might be a bit too optimistic) (and used for much lower), would push those people to get this Nikon one.
Compact cameras with large sensors are coveted but rare - the Leica Q3 and the Sony RX1R III dominate the market, but both cameras are extremely expensive. Rumors now suggest that Nikon is also developing a compact camera with a full-frame sensor that could be offered at a lower price.