Why is there no embedded c code in arduino libraries? When I took a look at how the arduino libraries were coded I expected to see register names like I/O registers(PINx,DDRx,PORTx) and other such registers with values assigned to them but instead I saw normal C code with functions and a class.

Why isn't there any embedded C in the structure of the library? Am I misunderstanding something very basic? Please help me understand.
If you take a look at the Arduino core library (e.g., the AVR version of
wiring.c), you will see lots of low-level register access. That's
why the core code is specific to a processor architecture.

Other libraries are built on top of the core API in order to be
portable.