Fitbit has brought a raft of changes to its most recent smartwatches with their latest updates. FitbitOS now supports faster access to the pair's SpO2 sensors and improved Google Assistant integration, among other changes.
https://www.notebookcheck.net/The-Fitbit-Sense-and-Versa-3-receive-new-features-and-refinements-with-their-latest-software-updates.542704.0.html
Stay away from the Fitbit versa 3, its good until you crack the screen and fit bit tells you they dont have a repair facility to fix them. You've been warned.