The term "became useless" implies that something was once functional or valuable but has now lost its usefulness or significance. Antonyms for this phrase could include "became useful," "improved," "enhanced," "renewed," "revitalized," "rejuvenated," "revived," or "restored." These words suggest that something was once ineffective or unproductive but has since become valuable or beneficial once again. By using antonyms like these, one can convey a more positive tone and outlook, emphasizing the potential for transformation and growth even in situations where something may seem to have lost its value or purpose.