Just a note: The above only work if you are with somebody like Xapo or Bit-X where your bitcoin wallet is directly linked to your card. The preloaded cards do not work like this and often its easier to just cash out than getting funds onto those cards.
So only Xapo or Bit-X that implement with debit card ?
No there are others who also offer debit cards but they work on a pre-load basis. This means that you have to send bitcoin to them and they then sell it to convert it to say US$ which they then load onto the card. So the debit card actually works like a prepaid card. There are also fees involved for this loading of the card which makes it more expensive.
With Bit-x and Xapo you do not need to send bitcoins to anyone. The debit cards they have are directly linked to your wallet. So each time you make a purchase on the card the value of that transaction is taken directly off your wallet. So no need to first convert the bitcoin to fiat, it all happens in the background when you make a transaction.
Well it is like the first case then it's better to sell to people or in exchange.
The second case is pretty good and like this should be pay with your bitcoin directly.