There are multiple competing authorities, but they are absolutely authorities, and their versions of individual texts are extremely close to each other.

Most notably, for the actual list of books there's the Catholic Church for the Catholic canon; the Masoretes for Judaism; Synods for the Greek Orthodox canon; and a broad consensus in the Protestant community.

For the texts themselves, the Septuagint and the Masoretic text are the only game in town for the Hebrew Bible, while the Greek texts of the New Testament were very firmly set in stone by the Imperial Roman Church (as central of an authority as it gets).

Note that some of these authorities (the Masoretes, the Imperial Roman Church) do not exist anymore. THat just means that canon is unchangeable, it still exists.

By authority i refer to lawful authority. Able to execute lawful enforcement and prevent editing and copying.

No one holds authority over the original texts. There is authority over translations though. But the original is open source with no license.

That is not the authority that I meant when I used the concept to explain how the Bible's canon is based on the existence of authoritative texts endorsed by authoritative sources.

You can make an edited version of the original Hebrew and Greek scriptures with whatever changes you want. But no one will agree to call it The Bible, because it does not match the text endorsed by the original authorities.

Same as how there still exists a Sherlock Holmes canon based on Doyle's work, even though you can legally write whatever you want even in contradiction to that canon.