I think for most folks it can take a little while to find your way around the limitations of today’s wearables and then be able to use the data to tweak metabolism.
So far, using Oura 3 and a couple of Garmin watches, I’ve found Oura to be more accurate with sleep reporting, although they both get it wrong and sometimes consider sitting quietly through a non-action movie as a “nap”. Still, I prefer Garmin for not having the gall to charge subscription fees just to find out what time it is.
I am encouraged also that Garmin has made their data somewhat user accessable. Garmin Personal API
Now all I gotta do is learn how to program Python.