Is 4chan the perfect Pirate Bay poster child to justify wider UK site-blocking?

I genuinely do not understand where how the idea of building a total surveillance police state, where all speech is monitored, can even as much as seriously be considered by an allegedly pro-democracy, pro-human rights government, much less make it into law.

Also:

Step 1: Build mass surveillance to prevent the 'bad guys' from coming into political power (its ok, we're the good guys).

Step 2: Your political opponents capitalize on your genuinely horrific overreach, and legitimize themselves in the eyes of the public as fighting against tyranny (unfortunately for you they do have a point). They promise to dismantle the system if coming to power.

Step 3: They get elected.

Step 4: They don't dismantle the system, now the people you planned to use the system against are using it against you.

Sounds brilliant, lets do this.

Simple. The UK is not a pro democracy, pro human rights state.

It might be uncomfortable to admit this, but if your government is a police state that's pretty much mutually exclusive with being a pro human rights state.

It does seem culturally popular in UK to have rules and government hoop jumping for every small thing, to the point it's become a tired meme on the internet. The backlash on this one was likely because it happened very quickly and very broadly across the internet at once. They should have slowly expanded the scope as most governments do and maybe the backlash would have been lower.