Yes it would and cannot be replaced. We all knew that bitcoin is the base of all other crypto currencies that are on the market right now. It is the father of every altcoin as it is the first one and it is the most popular. I also think that some altcoin will not surpass it. Yeah, still possibke but as of this time it is not. Maybe we just have to wait for a century for it to happen.
And as a father as you said, whatever the performance of bitcoin, the altcoins will also be affected. Take it for example just today, the price of bitcoin is increasing and look at ETH, it is also falling, so there's really a relationship..
When bitcoin is progressive, alts will fall so it cannot be replace when bitcoin continue to perform well.