it's probably not noticeable for a million files

the syscall is going to be many, many orders of magnitude slower than the difference between a direct and an indirect call

IIRC, switch statements bigger than a certain sizes are compiled to jump tables. So it's just a static jump after the code finds a working method.

In theory, it's a very cheap piece of assembly after that point.

With trivial method() functions, you could speed through that loop a million times in a millisecond.