But is the fruit just added to make it healthy? And is Pimms just a British thing?

Nope. The opposite.
It's how alcoholics can pretend they're drinking a "healthy" alcoholic beverage. Instead of admitting they're just taking the edge off with this Pimms crap. All until they get back on the hard liquor when they get in.
From your posts, the Brits are more different than I thought. It’s not here in the US. It is kind of like flavored vodka, but it’s freshly flavored gin. It reminds me that in the Caribbean a rum fruit punch is almost all rum because as they will tell you, fruit is expensive as it is imported and rum is plentiful and cheap. People here do drink Sangria at times.
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I'm so out of touch, I didn't realise the government were now recommending that we drink 5 Pimm's a day, presumably they are hoping there is a level of shitfaced that can be achieved that would cause people to forget how awful they are.
No I use it in mixed drinks or a highball from time to time
Creative.., I like it
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