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.

because Bitcoin and Altcoin are coin units that build and generate Cryptocurrency markets. so if one of them goes down, the other goes down too. but just to be calm for the decline will not last long.