why do you even insist on separating the two from each other?
it is like asking which one would survive longer, cars or combustion engines! bitcoin is based on blockchain technology and it is the one that introduced it to the world. bitcoin is also the one that is improving this technology and as the technology grows bitcoin grows and vice versa. they are not separate, they are one thing.
I agree with you on this. Personally I think that the introduction of Bitcoin led to the introduction of blockchain as well. So separating both of them doesn't seem ideal and therefore if any one of them will survive in the long run, then both of them, technically speaking will survive as well.