You're thinking of patents, not copyright. You can't copyright an idea, only the implementation of an idea. I could spend years perfecting a play, but when a troupe performs that play, I don't own their performance.

And you underestimate the idiocy of self-proclaimed 'vibe coders'. Go into practically any FOSS community and see what they have to say about vibe-coded pull requests. The people making them have no clue what the code is doing, they're just chasing clout with minimal effort.