I'm a little annoyed that I've lost access to the ios battery health feature too. But even when it was working it wasn't always accurate. My original iPhone SE battery said it was 89% healthy even though it was 2 years old and prone to shutdowns even with throttling turned ON. New ifixit battery is working great. Granted the health feature is still in beta, but still. The real purpose of the feature is to address the throttling complaints- give users a little more control over it , and cut down on panicked support calls from customers convinced their phone is being throttled. Its helpful in theory but in my case it wasn't working well enough before I replaced the battery to miss it much.