What is a good lightweight 24/7 heart rate and sleep tracker that's not a Fitbit? I have an Apple Watch but the Fitbit's sleep tracking is way better and I keep it on for days (whereas I charge my Apple Watch overnight). I am super happy with my Fitbit but given Google I assume it will be "sunset" within a year or two so I want to switch early.
I've heard good things about the Oura Ring https://ouraring.com/. It tracks sleep and has a 7 day battery life.