Altcoins are dying and some will be dead. Bitcoin murdered them and now I want to murder my self.
There's no need to worry my friend
Alts would not die because i can say that in the TOP 100, most of the coins have far more better use case than Bitcoin.
Most of the coins has a Blockchain, Can Sent/Receive, Faster Transaction Time. Bitcoin has all the following too except slower Block time. Bitcoin only serves for payment purpose and it is the "Currency" in the Cryptocurrency Scene.
Without Alts, Bitcoin wouldn't perform much
generally speaking you can see an actual downtrend wen bitcoin rise but this is all related to approaching x2segwit fork so nothing to worry about, after that money will get back to alts like everytime
consider that at actual bitcoin price level and fork price futures there is an instant return of 22% thanks to the chain split