Bitcoin is a very popular crypto coin today, we know that Bitcoin will be very expensive in the future but I imagine if Bitcoin die, whether there will be hope for the future of altcoin? because most altcoin exchanges are to bitcoins
your opinion is highly appreciated.

In my own opinion, if bitcoin dies altcoin will die too because both of them has a connection to each other. But it still depends in a situation like what if bitcoin dumps in the market and altcoin pumps up, altcoin surely would not die because bitcoin do not have anymore value if that happens.
It has a connection, but i think that if bitcoin dies many people would buy altcoins instead of bitcoins. This will allow altcoins to rise very high and take bitcoins place instead.
You can also see at the stats now that altcoin is rising just because bitcoin has dropped a little bit.