Even though bitcoin increase the demand everyday so, the price of bitcoin will rise and rise in everyday, the altcoin will stand forever as altcoin its because altcoin is rean source of bitcoin its because if earn more eth and you can converted it to bitcoin you also earn bitcoin in that way so, altcoin will stand strong forever even bitcoin is very expensive.
So your point is altcoin will survive because there is not relation if bitcoin price increase then the altcoin die. I thinks is not enough to say altcoin will survive. There are so many altcoin will die not because bitcoin price increase but because that altcoin has no popularity. Altcoin will remain survive because cryptocurrency need something work in different idea than bitcoin.