Look at the benefits of bitcoin.
* Works online 100%, 100%transparent for private and commercial use. Total control of private or public money for it's holder or holders, investors, governments etc.
* As It's works online there no need of expensive steel safes or bank deposits to keep your money safe. Any password or time code can be used.
* No fees. Unlike cash, hasn't 2%-3% of inflation every single year.
* Accepted for Food Shopping & Micro payments via electronic card.
* 0 confermations time, with introduction of "instant pay" function.
* 0 exchange risks in use of proper securities and competent insurance.
* any entrepreneurs is able to understanding of the value of payment.
* No need for pay terminal for small businesses. For small entrepreneurs it's a high expense of 70 bucks every month.
* Theoretically it's would not be needed to have an expensive licensed cash register, for small entrepreneurs, as every transaction is totally transparent. So cases of black money flow would be easily found and proven.
* Banking and gambling. No need of any verification for CFD,Stock,Currency or gambling services.
for me why bitcoin is better than cash it is because Bitcoin better than cash, I think this makes Bitcoin different or unique. Whether this is better than cash is more of an ideological or economic theory type of question, but being unique may be sufficient to ensure Bitcoin can have significant value.