Blockchain itself is enarly imposible for some individual to hack it or modify some things into the network unless he/she has 80% of the running nodes to modify them. Bitcoin was really made tough. Dont worry about it.
Destroyed how? You have to be more specific than that.
By what means, during what time period, etc. Because, eventually everything will be destroyed, including our planet, solar system, galaxy...
Nothing lasts forever. So please, explain your thoughts a little bit more.
You made my day bro hahahha.