BTC is the oldest and most popular crypto currency and it is very successful so that reasons will be the having high price.
That is not really enough of a reason for the price of bitcoin to be so high besides you're confusing cause and effect the price of bitcoin is not a high because it's popular, being popular is just the effect of something even greater, which is the technology behind bitcoin, the technology is what really makes the price of bitcoin so high and what it makes it so popular.