There is no lack of detail unless of course you zoom in like crazy, like with any photo. I’ve never had much of an issue with noise reduction being to strong and I’m well versed in the camera world as it’s part of my job. I have heard of those with issues but for the majority of people it’s not a problem. I get a new iPhone every year and throughly use the cameras so I am very attuned to any improvements or issues that may be present.

Sounds like your phone may have an issue if you have a lack of detail in general with your photos.