Today, there are many new digital currencies, but still bitcoin has a huge advantage in front of them-it is over its improvement and new products based on it that the best minds work, it is bitcoin projects that attracted huge investments from venture investors and corporations. Bitcoin has the largest community of supporters. I think that hardly the same success can be repeated by any other new cryptocurrency in the near future.
Most likely to replace Bitcoin, I doubt that someone can. Perhaps bitcoin itself will become less popular and will itself give way to the first place in the rating of cryptocurrencies.