Bitcoin is simply a "bubble", an asset that has no intrinsic value if its value goes to zero when the trust is gone.
The value and demand for Bitcoin will increase as only a total of 21 million Bitcoin is "dug out". In addition, the amount of Bitcoin dugout will decrease over time as Bitcoin deals, in other words, Bitcoin's demand will increase but the supply is not sufficient. This will increase the value of Bitcoin in the future.
The ones who say this thing that bitcoin is a bubble are not fully aware of the nature of this bubble, it is very much different from rest of the bubbles as it has this capability of rising high even after going down. All you need to have is some good knowledge regarding the things which can then help you in thinking of a way which can help you in making maximum profit from this bubble.