I ditched my Oura ring, I found that it really was great at tracking sleep HRV and RHR, but the battery doesn't last and it's just expensive e-waste after a year and a half
I got really upset with Oura when they tried to have their cake and eat it with regards to charging a huge premium for what is a very cheap device and then also a monthly subscription for something that does not need any subscription. I bit the bullet and switched to a Garmin watch for longer battery life and no subscription.
I now have a device that has way more features and lasts significantly longer.
What's the new device?
You're just never going to get a smart ring with a battery that lasts longer than a year or two until different/better battery technology becomes commonplace.
I've had a RingConn ring since December 2024, and I went with them primarily because they don't charge a monthly fee like Oura. But at this point the battery that originally lasted 2 weeks lasts only about 2 days. It's about the best you can expect from a ~30mAh lithium cell. Once it finally dies completely I won't be replacing it.