It's definitely not doing that; once you get something important, you need to handle it by using your phone.

The problem a lot of people have with doom scrolling is that there's basically no barrier to doing so except shear will power. Making the process more inconvenient, even if just by having to stand up and walk over to the phone, can make a substantial difference. If the notification is not worth the walk over to the phone, then the notification ceases to be a prompt to go doom scroll.

Hence you do not have carry your phone with you. The watch lets you be reachable in case of emergencies or basic communications, such as audio calls.