At least for my ex-fiancée it was about the link between husband and wife, plus tradition. It was basically “I’m married, you see?”. Just like a ring.
(We talked a fair bit about this stuff, as back then I was planning to add my maternal surname to my legal name. She was OK taking either surname.)
They evolved. Just like they would inside your body.
…in Brazil those are sold in skewers, people call them kafta. And yes, if you don’t take care while shaping them, they’ll look, well… not really appetising.