I don't think you understand what dectralization is, and that's the problem.

You keep saying x isn't, but can't tell me what is.

If you think the checking system isn't dectralized, I suggest you study settlement procedures. They happen every night, and the banks have to come to agreements (convergence) regarding the settlements of their accounts as between other participating banks.

I don't see how court process has any bearing. I can also sue someone over bitcoin. Nothing is immune to legal process.