Yes, you can use Galaxy Watch 6 without your smartphone. Initially, you have to pair your watch with the smartphone, and then you can use it. You need to be in connection when you want to synchronize all your health data to the phone. Also, to get notifications, answer or receive calls, update the software, download new apps, or watch faces, you should connect to your phone.
If you use the LTE variant, then you donβt have to worry about all these things. Only once pair Galaxy Watch 6 with the phone, activate eSIM, and you can leave your phone at home. All your messages, emails, calls, and other notifications will be transferred to the smartwatch.