Getting back to the OP’s question though, I can see someone getting by just fine in a cover band learning their set songs by ear or via tabs and learning originals strictly by ear and getting by.
But you would be severely handicapped in your ability to communicate with other musicians.
Someone trying to teach you a song would have to play it over and over or give you a recording to work from as opposed to just saying, “Cm, F7, Bb” or 2-5-1.
So, I think that is the actual answer to your question.
EDIT: Also, without an agreed upon framework of chords, any attempts at improvisation with other musicians would likely result in the proverbial CF.
But you would be severely handicapped in your ability to communicate with other musicians.
Someone trying to teach you a song would have to play it over and over or give you a recording to work from as opposed to just saying, “Cm, F7, Bb” or 2-5-1.
So, I think that is the actual answer to your question.
EDIT: Also, without an agreed upon framework of chords, any attempts at improvisation with other musicians would likely result in the proverbial CF.