So... no ISO standard is really free or open, just drafts which may or may not be similar? That sounds kind of shitty.

I think ISO would say the standard is open, but not free. You're not required to be a member of a working group to access the final standard, you just have to buy the book.

Which has created a history of languages that usually follow the standard quite strictly.

(Though, I do personally despise the non-free aspect, I can sort of understand it, considering history and the effort to standardise).