So, for the decentralized network to run, there must be some nodes online.
What happenes, when at some time, all nodes on the blockchain go offline? Like for some unpopular coins, all node operators lose interest and stop running the node one day?
Will the blockchain be dead forever?
Or is there a way to restore the blockchain network and make it "alive" again, if at a later time some nodes come back to run the blockchain again?
Yes it can happen with multiple reasons,
1. People losses interest in crypto.
2. or Some regulatory policy imposed which enables this ti do.
if all nodes looses interest impossible to back to life again, but if internet fluctuation it can be alive once online again.