Yes, AI can copy other humans just as humans copy each other. The quality of the content generated by AI largely depends on the prompter. While AI can certainly paraphrase existing works, it can also be creative and produce nearly 100% unique content if the prompts are tailored correctly. However, it's also possible for AI to generate complete bull shit. Same with the code AI produces, much of the code will be exact copies of other examples or slight variations while it can also produce totally new code that never been created before it can also make up non existent commands that will not work and don't exist. For me AI is a tool for both assisting in coding and writing new content and people who write it off as a trash generator are as you said going to regret underestimating AI.