Honestly I believe bitcoin is better since one you don't use your credit card so you don't loose you needed cash but instead your cash that you could easily earn back from mining. Plus, it's open to all ages unlike credit cards.
I think they are better cause we won't be improving and keep making cryptocurrencies if it is not better. As of now, because we are just in the early stages of cryptocurrencies, people or most people view fiat as a better mode of payment but this is likely to change because the technology and the society is changing, and cryptocurrencies is the best suitable currency in the digital world.