> I think of them as portable private spaces for crowded environments.

I used to enjoy opening a broadsheet newspaper while standing on a crowded tube. Nearly as much fun as stabbing fellow commuters with a brolly.

> Also great for wrapping fish and chips in.

Didn't they regulate-away the heavy metals in printer's ink, at around the same time they regulated-away selling fish 'n chips in newspaper?

That regulation was clearly wasted effort--newspapers disappeared once we got decent mobile internet and the fish now come stuffed with micro plastics. I long for the days when you could get some heavy metal with your chips.