Some manipulation is fine - cropping, dodging, burning, etc. is fine as long as you're not misrepresenting what was there, e.g adding or taking away too much stuff. A lot of wildlife, press, etc. organisations and competitions only want the real photo and not something that's been mucked around with as that usually ends with rejection or disqualification.
Straight up AI is really just cheating if used to represent something it isn't, or pretending it is a person's own work. A lot of companies now seem to be harvesting people's work to feed their AI engine for their own profit.