The decentralized system means if there are a lot of the core, and it's not just having a single core. It will be automatically put the wall to defend the system itself. A lot of the cores were running it, and it will simultaneously merge into a system. Imagine there are a lot of walls stand up in front of you.

To break the system you must need to do a lot of effort.

Must breaking over 50% of the core(nodes).