It is not true that the Bitcoin has no competition. Definitely speaking, there are so many other crypto currencies that compete to the existence of Bitcoin. It is just said to be have no competition because of the great advantage and popularity of the Bitcoin to all crypto currencies and as it the King of the crypto world.
In my own opinion it seems like bitcoin has no competition because its Altcoins Competitors are very far behind in almost all aspect and bitcoin is very strong enough for altcoins to compete.