Because I tried using LLMs to write a compelling copy for a landing page and it’s just not that great. I tried a lot. A real copywriter will do a lot of research about your ICP and write targeted copy.
This tell us more about your (lacking) skills at using AI than the state of AI tools themselves.
You're probably using the free lobotomized versions of LLMs, and shooting a one-off short ambiguous prompt and wondering why it didn't turn out the way you imagined.
Meanwhile people spend hundreds of dollars on pro LLM access and learn to use tool calling, deep research, agents and context engineering.