Why is a conjecture considered reasonable but not proven?

A conjecture is considered reasonable when it is based on observed patterns, empirical evidence, or logical reasoning, suggesting that it might be true. However, it is not proven because it lacks a formal proof that universally validates it across all cases. Until a conjecture can be rigorously demonstrated through mathematical argumentation or counterexamples, it remains an open question. Thus, while it may seem plausible, its truth is not guaranteed without proof.