There are several synonyms for the phrase "become poorer," which can help you to convey the message clearly without repeating the same phrase multiple times. Some of the synonyms for "become poorer" include "lose wealth," "experience financial decline," "suffer economic hardship," "decline in prosperity," and "sink into poverty." Using these words can make your writing sound more polished, varied, and engaging. Moreover, it can add depth to your writing and help you to express the idea in a more nuanced and descriptive way.