you’re thinking too much like a computer.
in human speech, when “quote unquote” is used, it’s typically obvious when the quote ends from the tone and pace of what is said.
the function of “quote unquote” is to reduce the awkwardness and increase the impact of reciting a quote by obviating the need to state the word “unquote” at the end of a quote.
compare:
He ended every speech with quote and carthege must be destroyed unquote
with
He ended each speech with quote unquote carthege must be destroyed
Try saying both out loud. I think you’ll agree that the second form sounds less awkward and more impactful


For others who (like me) never heard of this before:
https://jitsi.org/about