Is USD or USDC better?

I'm curious about the difference between USD and USDC. As a cryptocurrency and finance expert, could you help me understand which one is better? I've heard that USDC is a stablecoin backed by the US dollar, but I'm not sure how it compares to traditional USD in terms of value stability, usability, and potential returns. Could you elaborate on the advantages and disadvantages of each? Also, considering the current market trends and regulations, which one do you think is a more viable option for long-term investments? I'm eager to learn from your insights.