Dash is technically better than bitcoin in many aspects. But it is not about what is better. It is about adoption. Dollar is a piece of paper and there is nothing technically good about it. It has value because everyone accept it.

Coming to Dash, it is not even listed on major fiat exchanges like coinbase, gemini etc. If it becomes more accessible and more people know about it, definitely it has potential to beat bitcoin in long run. But it is not happening in short time as bitcoin has a huge media frenzy around it. Dash is just an altcoin.