Ask HN: A good personal health tracker/collection device?

I'm trying to collect my health data (heart rate, temp, sleep, etc.) to gain some insight. I've looked at quite a few bands, rings and watches, and haven't found anything good.

Problems:

Very uncomfortable to wear that it affects sleep

Not accurate enough

Data not easily exportable, or behind paywalls

Privacy issues (although this one can probably be worked around by not providing real identity)

In particular, I was eyeing on the Oura Ring, which had pretty good reviews. But they recently switched to a subscription model. This really puts me off because it tends to get downhill from there.

Have you found any good ones?