Webkit integration is limited to ONLY Apple Watch Series 3 or higher!
watchOS 5 integrates Apple's WebKit web layout engine.
It uses Safari's Reader Mode to display web pages.
Web content is supported in Messages and Mail.
There is no Safari browser in watchOS 5.
Starting with the watchOS 5 operating system, you can tap a web page link within a message to view web content that is optimized for the Apple Watch. No Other Smart Watch Is Able To Display Web Page Content!