There are many reasons for a currency to exist, first we need a new currency because we need to use it for our specific purpose, like we want to use that currency for banks, we use banks currency, but not all currencies are successful despite how advanced they are because they can not be applied in the real life.
Bitcoin is the only cryptocurrency that I would purchase and hold so I can cash the coins out later.
Yes bitcoin is the only crypto currency. That you should purchase and cash. Crypto world is full of currencies. New currencies derived time to time. Every crypto currency want to attract more customers to invest in them. I see only currency that is bitcoin that attract by people.
More and more people invest in bitcoin. The is the beginning era of bitcoin empire the empire which is long lasting and have no end. People interested in bitcoin because they know it is profitable currency.