vi macros are those magical things that one must just know. Once you know how to use them, its really one those things with regards to text manipulation that helps you convert manual O(n^k) tasks to O(1) task. And a lot of things in our industry can be reduced to text manipulation.

For the next steps: Perl.

vi is not vim. I don't think vi has macros.

vi does have it. https://math.berkeley.edu/~gbergman/misc/hacks/vi.html

vi does have macros.

it had it from at least 1990 or so (when i first used vi), and possibly from much earlier.