I wouldn't say that the Bitcoin has no competition because there are some people who like to use other currencies over the Bitcoin.
But the Bitcoin does have a major lead in popularity and worth ahead of the other currencies.
The competition is only with fiat but in crypto world, bitcoin is obviously leading them all and if bitcoin will continue to succeed the crypto market will also progress as a whole. For now we should be thinking that bitocin and fiat are different and if we compare it with bitcoin, we know already that bitcoin is nothing compared to fiat which is most widely use in this world.