The term "more declining" implies a further decrease in value or quality. Antonyms for this phrase include "increasing," "improving," and "growing." These words indicate a positive trend in quantity or quality rather than a negative one. Other antonyms that can be used include "rising," "thriving," "advancing," "progressing," "flourishing," and "prospering." Each of these words suggests a favorable change from the state of decline implied by "more declining." By choosing one of these antonyms instead, you can add a more optimistic tone to the conversation or text being written.