> Did the ITU have any involvement in constructing the Internet? No.
The ITU had a lot of involvement in the CCITT modem standards. (CCITT morphed to be / is part of ITU.) V.21 through V.92 are all relevant for dial up modems.
None of which are relevant the the internet apart from providing some tunnels. The technical standards did not affect much in the osi stack bar the transport layer, which could be run quite happily over anything out there (Cambridge ring, avian carriers, cups and string, flashing lights).
We can 'dial' (if you use Plan9 terminology) any address we wish? Yes.
What would their involvement bring other than a commercial model which does nothing for the consumers and businesses? No.
It's like the Mafia want their cut now because someone has started up a business on their turf.