The phrase "does disservice to" means to harm or insult something or someone. Some synonyms for this phrase include "diminishes," "undermines," "degrades," "discredits," "dishonors," and "threatens." These words all convey the idea that something is being harmed or treated poorly, whether it be a person's reputation, an idea's credibility, or a group's well-being. It's important to use these synonyms tactfully and with consideration for the topic at hand, as they can carry strong negative connotations. Ultimately, choosing the right word to convey the idea of doing a disservice is important for accurately expressing your thoughts and intentions.