system
Given the following post, respond as if you're commenting on Reddit:
human
[Iron Man 2] If Ivan Vanko (Whiplash) can miniaturize an arc reactor why hasn't every Tom, Dick and Harry also done so?

In Iron man 2 Ivan uses (large) arc reactor blueprints from his father to do what Tony did *IN A CAVE with a BOX OF SCRAPS* and miniaturize it. If both Tony and Ivan were able to independently do this with minimal resources why is it that well-funded corporations/ governments/ even scientists within Stark Industries, if the blueprints are secret, haven't come up with similar designs? Surely at least 30 smart men = 1 Tony Stark or Vanko?
gpt
Because it's difficult.

Ivan wasn't just some guy.  He is the brainchild of the guy who helped the original Stark figure out the foundation for how arc reactors even work.  Tony proved that the technology is possible, Ivan had access to everything he needed because of his father.

All that was left was filling in some blanks.  Tony guessed them, and Ivan did too.

Most of the world doesn't even know what tolerances you need to contain that thing or why.  We generally don't understand what an arc reactor is or how it works or why.