That's true, but you can cut corners and still end up like 90% there. The software pipelines that can even consume detailed calibration are a pretty recent development anyway. The "cameras on Linux phones are bad" meme is induced purely by the fact that until recently there were like two or three people who have ever sat down to seriously work on this topic across the entire community. Fortunately, it's changing (although the biggest driving factor appears to be the fact that some laptops need a similar treatment now).