Litecoin is faster, monero is more private, ETH has smart contracts and there are much more altcoin with much more features, even Bitcoin Cash is faster than Bitcoin, but BTC keeps rising much faster.
Don't you think it's just because of the name?
People only want to make more money and bitcoin currently offers exactly that, and relatively reliably as well, since major players have started to enter the bitcoin market as well. That is enough reason for your average person to invest in bitcoin.