Which AI generators create images of enough quality to meet Adobe Contributor requirements?

People who think that AI is the next California Gold Rush are likely to be disappointed.   Only a few folks got rich from the Gold Rush  -- the shopkeepers who sold the supplies. 😉

Midjourney charges extra for bandwidth & server resources needed to generate high resolution (upscaled) diffusions. 

And you need a tier-2 level membership or higher to receive copyright (extra fees apply).

For best results, you'll also need to upgrade to a private account away from the group surge on Discord (extra fees apply). 

If you do a lot of art diffusion , the costs can mount up rather quickly. 

AI is not perfect.  5 legged horses and clocks with 6 hands are just a few recent examples of AI blunders.  Even subtle mistakes can ruin an image for technical reasons.  Closely examine whatever you generate at 100-300% magnification.  Fix all imperfections manually if you can or discard the images.  DO NOT attempt to upscale low-resolution JPGs afterwards.  The results will be worse than what you started with.

Hope that helps.  Good luck.

Resolution is only one of the issues (but it is a big issue, for sure). Some people upsample, but this is forbidden, and usually terrible to look at.

Anther key issue is that AI often makes errors when creating "reality". Look especially at small details, like fingers. Too many or too few fingers is a classic detail. In a "real" AI, everything must look realistic. For stylised artistic work there is more freedom, but you still need to count fingers.