For me Bitcoin has been my 100% portfolio and up to this point, I am glad that I choose that part even though Bitcoin price has undergone a lot of changes lately, my BTC vs $ balance has shown green and also red-negative movements which is a pointer to the activeness of bitcoin volatilities.
I'm glad to hear, you managed to form a clear idea of the crypto assets worth adding to the portfolio. Even though there are many other competing crypto assets, the cryptocurrency market is still dominated by Bitcoin. Overall not all cryptocurrencies are created equal, although there are some Altcoins that investors may find useful, Bitcoin remains the top choice.
Bitcoin has better investment fundamentals than most of the other altcoins. Bitcoin is the most bought, held and traded cryptocurrency on the market, it is only natural that you choose to fill 100% of your portfolio with Bitcoin.