I believe that they're popular mainly because well it was the first of all cryptocurrencies to be made. Honestly most of the other coins are scams and greedy ways that the developers make money. The only other coin I can think of that isn't a scam are dogecoins! What do you think?
Bitcoin is the most popular because it was first created by Satoshi. Bitcoin is the mother of all crypto currencies so that's why it has the highest volume and price as compared from altcoins. Also, many merchants have adapted Bitcoin as mode of payment like bills thru online that has no fee and hassle free. Many people have already became rich because of trading in Bitcoin so I just want to experience it as well. That's why we need to invest today and hold until we have reached the desired income.
