Right, but you can have entries in a block chain that indicate previous entries are no longer valid, or have modifications. Calculating a final state by walking through all the blocks in the chain. ( A bit like a CQRS based system can have a particular state at a point in time by replaying all events up to that point)

Doing it in such a way also makes auditing what’s happened much easier since changes are inherently reflected in the chain. You want to know when (or by who if you keep that information) a record changes, it’s right their in the chain.

Conservatives? The UK’s current government is not a conservative one.

Though I don’t think the political leaning of the party in power matters here, as this is what governments do in general. Find ways, and justifications, to expand the scope of their power, often by using “desiring safety for insert demographic here (usually children)” and managing to get it through. Often without thinking what future, potentially more tyrannical governments, might do with that power.