This has more to do with the ISA than C I'd assume. C was built as an "easy assembler". Furthermore, the computer doesn't really care about structure (in the structured programming sense).

In this case the implementation of the ISA stores information on each 'ret' depending on some 'bl' that came before. One can imagine that a different optimization technique which actually leads to a speedup exists. Without a branch-predictor, the program that Matt wrote might've been faster.

Imo, this has nothing to do with paradigms, but how control-flow interacts with the system. This interaction is different between different implementations of an architecture.

Code written for Cache-locality and paradigms that work well with it, for example, only became a "winner" after caches were widely implemented. Before that, the cost of sequential array access and random array access was identical. With caches, a linear search for an element can be faster than a binary search, even though it requires a lot more memory accessess. Thus, the optimal implementation for finding an element in an array is now dependent on size as well. (I.e. after an ordered array reaches a certain size, binary search should become faster on average).