how is this bad oop?
You have a function that operates on a struct vs having function pointers on a struct that operates on the values of the same struct?
taking in a pointer to a struct as an argument is much less overhead for the programmer than "ok this is an 'object' here is why it is doing what it's doing oh here is this method etc etc"
libc has stood for quite a while without OOP.
I think a mix of fp and imperative is magnitudes easier to mull about than oop.
imo fp and imperative semantics are much clearer than oop.