I was very surprised by work put into making replacing the battery easy on the Pixel Watch 4. They designed in screw actuated clamps for the back face. Hopefully this carries over to the 5th edition.

https://youtu.be/3pQWBFBIU2U?si=HEefZLDiIurcBj5K&t=61

https://www.ifixit.com/Guide/Google+Pixel+Watch+4+Battery+Re...