"Come down to" can be replaced with a number of different synonyms depending on the context. For example, "boil down to," "center on," or "focus on" could be used to indicate the central idea or main point of a conversation or argument. "Reduce to," "simplify to," or "distill to" may be more appropriate when discussing a complex issue that needs to be simplified. "Resolve to," "lead to," or "culminate in" might be used to describe an outcome or decision. Other possible synonyms for "come down to" include "converge on," "amount to," "result in," and "arrive at." The choice of synonym should reflect the specific nuance and tone desired for the sentence.