Because there is nothing inherently modern about this code, this is how C has been written for decades if not from the very start (I think you will struggle to find patterns in this code that are not covered by KnR).
That being said, there are books that cover relatively new developments in the C language and its ecosystem, such as "21st Centry C" by Ben Klemens (but even this book is something like 5-10 years old).
https://github.com/BoschSensortec/BMP280_driver/blob/master/...
...?
Because there is nothing inherently modern about this code, this is how C has been written for decades if not from the very start (I think you will struggle to find patterns in this code that are not covered by KnR).
That being said, there are books that cover relatively new developments in the C language and its ecosystem, such as "21st Centry C" by Ben Klemens (but even this book is something like 5-10 years old).