Meteor RPCs look cool, I've only started to see this elsewhere in frameworks like Solid.js. Was Meteor the first web framework to do this kind of seamless backend calls from the frontend?
While today I might re-use _some_ code, like helpers or TypeScript types for API responses, by and large I feel like that dream is unrealized and probably a never great dream in the first place. In practice there just weren't a ton of wins from doing so, as there were not many cases where you needed the same code in frontend and backend.
For the uniformed, like me, here's a meteor RPC - https://guide.meteor.com/methods.html