What is more secure than blockchain technology?

Blockchain is NOT "secure," Blockchain is simply more resistant to tampering than other highly insecure systems.

More secure is a centralized system. More secure is having regular backups that are stored offsite. More secure is to have only one entry point that you can continuously monitor than a million entry points and no way of monitoring any of them.

An adhoc network has the problem of bad actors, you can never know who a bad actor is unless you ask other people in the network. This means that, in effect, if you manage to inject enough bad actors into any adhoc network you can control the entire network and no one can do anything to stop you.

North Korean thieves are far less likely to find something that you wrap up in an old newspaper, label it “mackerel”, and hide in the back of your freezer.