This is essentially the same question as
Julia: Flattening array of array/tuples
but for array of Strings. The Iterators.flatten(xs) solution shown in the above thread is excellent for numbers. But, with Strings, Iterators.flatten() flattens a String into characters!

julia> f(xs...) = collect(Iterators.flatten(xs))
f (generic function with 1 method)

julia> f("oh", ["a", "b"], "uh")
6-element Vector{Any}:
 'o': ASCII/Unicode U+006F (category Ll: Letter, lowercase)
 'h': ASCII/Unicode U+0068 (category Ll: Letter, lowercase)
 "a"
 "b"
 'u': ASCII/Unicode U+0075 (category Ll: Letter, lowercase)
 'h': ASCII/Unicode U+0068 (category Ll: Letter, lowercase)

How do you get an Array of Strings from a call like f("hello", ["a", "b"], . . .) ?

It would be nice if you can tell the iterator to regard String as scalar.