BTC can't be better or worse than cash, it is just a different thing, BTC is like stocks, you can invest cash in it, but you still can't buy grocery for BTC
Don't be too sure about it. Although Bitcoin is now treated like an investment asset, if third party payment processors such as BitPay gets popular, it may be used for normal shopping and bill payments. At least in some sectors, it will be able to replace fiat cash. By fiat cash, I don't mean banknotes and coins. Rather, I was referring to PayPal/Visa.