I'm not using any other crypyto currencies instead of BTC and many other people also could think like this so BTC has no competition in the market right now
But not till the end until the new advanced technology which is more attractive than block chain there is no competition to bitcoin
Bitcoin is the most popular crypto but the competition is growing.
Maybe for now its still bitcoin which is leading them all, with the dominance it's clearly bitcoin is the king, however there will be more adoption in the future
so we have to consider possibilities.