I bought an Oura ring just to track my sleep, but after a couple weeks stopped using it because I didn't trust or get any value from the data. Nights that I tossed and turned and was up multiple times would score highly. Nights where I slept great and woke up refreshed, the Oura would say I would need to take it easy and recovery due to poor sleep.

I was gifted an Oura 4 last year and thought it accurately tracked my sleep. But a couple months ago, the sleep debt metric went flat to 0 even when I tagged poor nights of sleep (mainly due to child care).