The price and, ultimately, the charts on any given exchange are determined by the price of the most recent transaction. How can the prices of 100s of cryptos all move in the same direction at the same time?
As Bitcoin is the highest market capitalization among all the cryptocurrencies we have right now than most of them I believe are just following Bitcoin.
So for me, especially when I am doing trading I rather trade Bitcoin than trading other altcoins especially other high market capitalization altcoins which just correlate with the price of Bitcoin most of the time, so for me, it's just the same, volume on Bitcoin is higher.