I have a different memory than you regarding the expected lifespan of the ring, which I think was 1-2 years with normal usage. I don't plan to get one, but it certainly hasn't soured me on the brand. There's pretty clear tradeoffs involved with putting replaceable or rechargeable batteries in such a small device.
Some people were very upset that iPhones didn't have replaceable batteries like Blackberries. But it would seem that pretty much everyone got over that. With even tinier devices like AirPods and smart rings, it would seem like even less of an e-waste issue. I say this as someone who has no plans to get one of these things, FWIW.