All of my work was rejected based on quality standards and I wanted to get your feedback on why.

The onion should have rings.

Quality issues is more than the stock text, that is attached to all Quality refusals. And with generative AI, you will haven even more possible causes, due to the rendering errors that the generative AI tool creates. 

Moderators simply can't indicate the isue in the asset, for several reasons. First there is the time factor. Moderators simply do not have the time to give an extensive analysis with their findings. That would extend the moderation delays to years and decades. Then, moderators refuse at the first issue they see, but the asset may have multiple issues. So pointing out one issue only would encourage you to correct only this issue and to resubmit, just to learn again that the asset gets refused for a second, third and fourth issue. If you get a refusal, best is to ask the community and learn from their remarks.

This said, in addition to what @daniellei4510 said, you also have cutout issues. I'm just showing 3 of them, there are more: 

And I have indications that show that all of your asset is very slightly transparent, which could be an issue depending on the assets use:

I've added the green points to show my findingings. The green points are 100% opaque, the red shows where there is some transparency. You see that your asset is nearly everywhere transparent, my guess is 1/256 or there around (transparency is defined on a scale from 0 to 255 in such an asset, where 0 is opaque and 255 is full transparent). Depending on the tools the moderators have to check this, their view of your asset will simply be like this.

야채의 형상이 비정상입니다.
100%로 확대해보시면 확인됩니다.

Rendering errors. Some touch up is needed. Would the tomatoes be cooked with their stems still on? Mutant broccoli.

I'm aware that common problems may include noise, artifacts, over-processing, or focus issues, but I would really appreciate more specific feedback on what exactly is wrong with this image so I can improve future submissions.

The image was created using an AI tool . Any detailed critique or suggestions would be greatly appreciated.

Thank you!