Quick search on Apple store (Canada prices):

Watch series 540mm, sports band, gps + cellular: $659 AirPods and regular charging case: $219 Combo = $878

iPhone 11 = $979

You could pick different models to make either case true (eg. iPhone XR is $799, watch series 3 cellular is $429). But nonetheless watch + AirPods is pretty close to the price of a phone it seems!

The xr starts at $600. It’s a rich person fantasy that you’d go for two fallible devices which work poorly for basic things like texting, ride hailing, looking up menus rather than one device that does more.