But for many years no one did this, except very rarely. And the honors were left to some folks in the US, IANA/ICANN. Do not be fooled by the acronyms and the fabricated processes and formalities on the official websites. IANA was essentially one person. Bless the hearts of those who worked to create the early internet but these "organizations" derive their "authority" from nowhere. The internet is an abstraction, a term to describe different networks that cooperate.
The generally static nature of the root.zone file changed recently. It has doubled, maybe tripled in size and is now filled with TLDs such as .loans and .cologne. As well as trademarks such as .google, .microsoft, etc. These can also capture traffic from users who type strings into address bars that are not FQDNs.
ICANN charged $85K+ just to bid on these beauties; they made some very easy money. Most of them are worthless. Exit time for ICANN. :)
Now that it is filled with garbage, and perhaps anticipating some finger-pointing, it is time to acknowledge that the root.zone belongs to everyone and is managed by all countries of the world, not only the US.
The "transfer". More fabricated formalities.
The truth is that anyone can exercise control over the root.zone file, and anyone can serve it. Whether you choose to follow them or not is up to you. (Most users just let default DNS settings decide this for them.)
Similar to the early IANA, one person can do this job. I maintain and serve my own root.zone. I am the only user but there could just as well be hundreds of users. This could grow to thousands which could grow to millions which could grow to hundreds of millions which could grow to...
This is what happened with the DNS. It started out small and grew big. Believe it or not it is still not that big. I could fit all domain names in existence on consumer-sized storage media.
Thus concludes an opinion. Mildly informed.