Actual thought I had in the shower!
Gelatin was originally and still often is derived from meat by-products, so wouldn’t it make more sense as a meat dish?
I looked it up, and it turns out that accounts of aspic (a savory gelatin dish) predate the earliest record of gelatin desserts by more than half a millennium!
Maybe the mid-20th-century meat Jell-O trend makes more sense than I thought
I mean, cream comes from a cow tit but it’s still pretty useful in dessert. Eggs come from a chicken butt but are vital for most desserts as well. And if you look up pictures of aspic, well, there’s a good reason you don’t see it often anymore.