As AI is a very controversial topic, I will decline to leave a star rating for AI dungeon. Much has been said about how AI could destroy jobs and undermine human labor. I agree that these are legitimate issues which need discussion. I don't have the solutions. In any case, starting here, I will stick to approaching this as a reviewer evaluating a product.
AI dungeon has been revised with different models over the years. When I first tried it, Dragon and Griffin were pretty crappy, while GPT-3 was at least somewhat competent. With the release of later models like Mythomax, Mistral, and so on, I will admit that it has gotten better, although it's still not good for creating a lengthy story.
AI dungeon does require a bit of 'effort' to use, in the sense that you will have to type out the starting paragraphs if you do not want to use a preset beginning, and if you want to guide the story or modify existing outputs, you'll need to type out the sentences in full. For folks who are just used to tapping on choices, some effort is needed here to make the story work for you.
AI Dungeon is better at writing scenes than coming up with long plots, as it merely examines the chunk of text before it, depending on context lengths, and comes up with what it thinks is a statistically appropriate follow up passage. If you want to play around with scenes, AI Dungeon will work for that, and can be quite good at that. However, it's pretty useless for telling long stories, unless you don't mind a long story which goes in some random direction without a care. Due to the nature of AI, plotting is still something it can't do, although anything is possible in future with this rapidly changing technology.
Personally, I prefer it to Novel AI.
It's good for a bit of free entertainment, and the free models can be used to trial the software before deciding if paying for a premium subscription is your thing. Personally, I got bored with it in a month or so, but I might come back if something new comes up.