Bitcoin does not need altcoins.
Unfortunately it does.Suppose there were no Altcoin, people would switch back to fiat in bearish times and chances of them coming back to btc were less. Now they have an alternative in Altcoin and any fall in btc price is comepensated with the rise in Altcoin price.
But yes there should not be hundreds if Altcoin. I think only 20 would have been better.
Bitcoin can indeed live without altcoin, these coins can still be paired with FIAT, but you have to remember, strong price fluctuations one of which comes from altcoin market activity, if Bitcoin live without altcoin, we will not see bitcoin price could be as high as now. major currencies require booster in trade market, here altcoin play to make bitcoin as a benchmark of cryptocurrency.