Bitcoin doesn't need altcoins because it was making its way by its own.Altcoins are dependent on Bitcoin which has been seen over and over again on every rise in price of Bitcoin.Bitcoin will always rule the digital/crytpocurrencies no matter how advanced they will be in tech but still will remain under Bitcoin
Not all of your statements true mate, i am not totally agree with you. Alternative coin to be comparator with bitcointhat can point out that bitcoin still and keep on the top of Cryptocurrency. But you are true if the fluctuations alternative coin isdown dependent from bitcoin price.
For nowadays and maybe for few many years later bitcoin will conquer the Cryptocurrency . But no one knows if there is some new biggest development on Cryptocurrency and appear a new coin that will can compete bitcoin with as well.