Prompt Engineering is not a profession. Prompt Engineering is a skill. It is the ability to write effective prompts for Generative Models like ChatGPT, and it can be potentially useful in many professions.
In the same way that millions of professionals use Word and Excel in their daily jobs, people will need to write prompts for Generative Models to accomplish their tasks. But this does not mean that there will be a category of specialists that will be paid to spend most of their time writing good prompts. If you don’t like the example of Microsoft Office, we could also say that ChatGPT is only a tool, in the same way that Figma, Jira and Git are tools.
But in my opinion it is even more important to understand that the effective usage of Large Language Models (LLMs) such as ChatGPT requires Domain Knowledge. A professional must have previous experience with the domain in order to write good questions, and also to be able to validate that the responses produced by the model really make sense.
A person must have previous Domain Knowledge to be able to write a really effective prompt in this domain. So, for example, if you would like to ask ChatGPT to produce an amazing travel itinerary to some touristic destination, you must include in your prompt the important aspects you are looking for. If you are not able to determine the building blocks that compose a great travel itinerary, you will not be able to optimize your prompt.