Just to let you know, the invention of bitcoin is what begot altcoin, bitcoin has been in existence for long before altcoins where been created, bitcoin being the oldest is the most popular and trusted cryptocurrency so far and this is more reason which it's at the top, no matter the condition of a father he is still the head of the family, the fact that the new blockchains are doing much more better than bitcoin doesn't mean bitcoin has lost it's purpose of creation.