The evidence the tier system is currently working now amounts to 2,220 people on the Isles of Scilly, right?

If the government is continually having to raise the tiers in virtually every corner of the country, that means tiers aren't working - they're just waiting.

Regional tiers make some kind of sense if they're at least keeping infection rates stable, so they don't have to be raised everywhere.

That's not a 'because London' point - last summer it was difficult to justify having the same measures in, say, Cornwall as in Leicestershire.

But if you're having to raise the tiers in most of the country every week or two, that doesn't just suggest the strongest restrictions aren't working - it also suggests the lower tiers are just delaying the inevitable

Outside Scilly, nowhere in England is now in tiers one or two

The fundamental metrics of this crisis have been infection levels and rates, and it's beyond dispute - three waves in - that the choice is between strong measures early and even stronger measures late.

Waiting for every last statistical droplet of incontrovertible proof that strong measures are required is logically defensible - it just has a bad track record in the pandemic.