No, is the short answer.
If you always have your iPhone nearby, then you can use a GPS only Apple Watch (less expensive and no monthly fee), and it will do everything the cellular model does, by using the iPhone’s radios. Where nearby is somewhere in the same moderate sized wood frame constructed home.
If you go for a walk, run, bike ride, etc… with just your Apple Watch, it can record your exercise, and when you get back to your Apple Watch, it will sync the data collected. You can also play music stored on the Apple Watch. Of course while away from the iPhone, the GPS only cannot make/receive phone calls, messages, nor access the internet.
An activated cellular model, shares your iPhone’s cellular plan from one of the carriers listed here:
Apple Watch - Carriers - Apple
and you pay an additional $10 U.S. per month to add the Apple Watch to the iPhone plan.
The activated cellular Apple Watch can leave the iPhone at home, and still get/make phone calls, messages, weather, stream music, etc…