It’s not a single villain. It’s a whole cast of characters. In England and Wales, you’ve got regional water companies.
Think of them like the wizards of your local plumbing system. They each have their own pricing spells.
Move from Yorkshire to Severn Trent? Your bill can change by hundreds of pounds. It’s like paying different prices for the same pint of milk depending on your postcode.
And Scots, you lucky ducks. Your water is bundled into your council tax. No separate bill to panic over. Cheers to that.