You have really taken time to state the good features of nano and that's wonderful. Let me ask, why was Ethereum, Litecoin etc created? Most think they can beat Bitcoin on the long run, but where are they? Bitcoin passed through challenges and today it is highly valuable, that is to say, the tougher days only strengthened Bitcoin. Let me ask again, how many year has Nano lasted? Ethereum with all its team is yet to beat Bitcoin all these years, now it's Nano.
However, it will be hard for any coin to beat Bitcoin not after paving the way for them.
Adoption is one major difference for most of the altcoins as compared to bitcoin. The popularity of usage is incomparable when it comes to bitcoin. Nano might have the best features but how many users are actively using Nano as compared to bitcoin? If you say crypto to an ordinary individual, what comes to his mind first? Bitcoin or Nano? Come to think of it...