Analogy here is somewhat like coke and water, good to have both. But there's always one better depending on the situation. I for one would like the best of both worlds so I invest in both alt coins and bitcoins. Both side of the cryptocurrency coin is best when you have both at your disposal.
Good analogy. Anyone who is interested in a similar question, I advise you to study the technical documentation of Bitcoin and the Altcoins of interest, you will immediately understand the difference between the projects, how they differ and what are the advantages of each.
But any of them have their own advantages. Remember you can see more than 300% pump in altcoin but it will be so difficult to happen on bitcoin. We must always to diversify our portfolios to decrease the risk of our portfolios. It's a must to diversify our portfolios before try to invest in the crypto.