Well it is simply that cash really works offline and it is the traditional way. This is the way of trading where we became dependent to it. Having a cash in real life is the traditional way of living, means that every people used that especially our elders. But bitcoin is the new money or new currency. But I think we need to cope in the future. And this is the future, this is bitcoin. The next generation of currency.
As for now cash is better than bitcoin because you can use cash anytime you want and it's so easy to bring with just your wallet.
If people are really want to use bitcoin in the future as for their daily needs such as riding: bus, train, plane, ship etc., then i think we need some kind of a bank for our bitcoin that can easily be used for our everyday needs.