Yes, I had whoop for a few years, apple watch, gamin watches… but they don’t track food (at least not automatically), and they can’t separate life stress from training stress and sleep can be off for some people. HRV and resting HR seem to be mostly accurate but have strange fluctuations at times too… but for sure worth learning about the data and seeing how it works for you. But again it’s the full picture that is important and collecting it all religiously.
I had the 2nd HRV app in the app store (long before whoop), and a 4 gold metal winner ice skater sent me an email that told me thanks my app really helped her. The whole US speed skating team used it back in those days…
So yes I would say if you understand your body, and understand the signals coming from the better garmin watches, apple watch, whoop or signal that is the strongest method of understanding your recovery. I would try this fitbit air some time as long as they give raw data access automatically.