The antonyms for the word "more never-failing" could be "less reliable", "inconsistent", "unreliable", "undependable", "untrustworthy", "unreliable", and "fluctuating". These words indicate the opposite of the reliability and constancy inferred by "more never-failing". An object, a system, or a person who is inconsistent or unpredictable cannot be relied on to perform consistently or deliver results consistently. It creates a lack of trust and confidence in the entity, leading to problems in various situations. Therefore, the antonyms of "more never-failing" reflect the quality of unreliability and lack of consistency in performing a task or fulfilling a commitment.