Many people buy coins that they simply like, you need to study projects and look for prospects, and see how their technology and coins can come in handy in the future. XRP has more advantages than bitcoin, but this is my opinion.
Every coin has their own platform and purpose. Thus they also have distinct advantages. Bitcoin's purpose and platform I think is the basis of all altcoins that were made in cryptocurrency. Thus, it proves that it has more advantages than any of altcoins.