In the previous March update, Google claimed to bring a battery saver quick setting toggle button to the Pixel Watch. When the firmware was released on the watch, none of the users received a new toggle. When enquired with Google, it said it will separately introduce it and looks like the company has finally rolled out a new quick settings toggle to the smartwatch.
You can find the new toggle in the quick settings screen. Previously, users have to open the Battery Saver page, and then scroll down below to activate it. All users have different habits of using their watches, so heavy users always require battery saver method at the end of the day to save some juice.
The small update can now make a big impact on those heavy users to access battery savers. Note that, in this mode, the watch will turn off most functions to save more power for essential functions. The rollout has begun, and you will notice it when it reaches you.