It takes time and effort to get noticed! You should appear higher in the list if you click on "Most Recent" or "New & Popular". But to actually gain popularity you will need to market your assets, just creating an account and dropping a couple of posts will not get you a huge amount of traffic. 

As for the asset pack itself, first of all the inconsistent style in the example images doesn't look too appealing. I know you said only two styles in the pack (realistic or cartoon) and so you are showing those two styles, but anyway it just makes it look like a random grab-bag of images rather than a coherent package that all fits together. The page itself is very plain so that isn't really selling it either.

Secondly, the AI errors present in the images are pretty obvious and make it look less professional.

Thirdly, many people will simply not want AI created art, myself included. Especially here... Itch.io is very indie-centric and full of real artists who work hard to create their art. AI generation can be viewed as stealing from artists, since it can only function by learning from existing content created by humans. Even if that content is free, it is disheartening from an artist point of view to see that free content regurgitated by a computer and then sold for profit. Also, anyone who does want to use AI could probably just generate their own backgrounds.