Which? is a UK brand, and in the UK it's fairly common to see the postcode (or rather the first couple of digits) used to determine which regional programming a user wants, given the (to some extent historical) TV regions and channel numbering.
I've seen "always offline" pre internet era satellite TV set top boxes do this, and use the first 2 or 3 characters of the postcode to work out the correct region and show the correct programme guide information and channel numbering.
I imagine that on a modern internet enabled device this might also pre-select some of the "watch later" apps, based on your region.
Doesn't mean there's no wider issue about data gathering and exfiltration over the internet, but just to add some regional context as this postcode point might not be as egregious as it sounds at first.
I've seen "always offline" pre internet era satellite TV set top boxes do this, and use the first 2 or 3 characters of the postcode to work out the correct region and show the correct programme guide information and channel numbering.
I imagine that on a modern internet enabled device this might also pre-select some of the "watch later" apps, based on your region.
Doesn't mean there's no wider issue about data gathering and exfiltration over the internet, but just to add some regional context as this postcode point might not be as egregious as it sounds at first.