I don't think Altcoins are better than Bitcoin, especially if you look at the average of Altcoins, there are so many useless shitcoins made only for profis of the Devs. I agree there are some good Altcoins, like ETH, but finally Bitcoin is still number one.
But ETH is very useful for me. So Bitcoin and Ethereum are good ones.
If measured by stability, popularity and of course no one can beat bitcoin, but if we aim for big profits then altcoins are more promising than bitcoin, altcoins can rise up to hundreds of percent per day while this is almost impossible for bitcoin.