At this point, language isn't a barrier. I read and write Russian without knowing how to read or write Russian. I regularly talk to my Russian friends in Russian thanks to Google Translate.
It may have taken a bit longer than the 1954 prediction said, but it did happen.
67 years have passed and we still need translation for many applications.
That’s not an indictment of the technology; only of the extreme optimism.
But in 1954 there were no web pages and reading articles or papers published in foreign languages was extremely rare. Nowadays, these are all translated instantaneously for free by modern web browsers with reasonable fidelity. And odds are these make up the overwhelming majority of the foreign language material a modern person consumes.
I imagine the pairs of languages plays a part, and of course the prose.
Regardless; there will always be ambiguities, and many sometimes-important-subtleties are bound to be lost in translation. Even when a professional human does it.
(Also your prediction being half a dozen decades late isn't particularly useful.)
To corroborate your point about Google translate, that’s exactly what writers used to create gobbledygook language for the malfunctioning robot in The Good Place. They literally used the tool to translate his dialogue from one language to the next so it would be semi-incomprehensible gibberish