Series 7 watch
How do text messages work on series seven cellular watch?
Apple Watch Series 7
If you are talking about traditional SMS/MMS TEXT messages, read the footnotes on this webpage
https://support.apple.com/en-us/HT205547
1. To receive SMS, MMS, or push notifications from third-party apps on your cellular Apple Watch, your paired iPhone must be powered on and connected to Wi-Fi or cellular, but it doesn't need to be nearby. You also need to be signed in to iMessage on your iPhone.
iMessages uses just the Internet, and does not need the iPhone as a relay, as long as you have cellular LTE service.
