First off, what is the dpi? Second, what part is sharp and clear? Adobe stock requires so much more from photographs. Look at your work at least 100% better yet 200 - check every inch. If you can not focus this shot, it will not be accepted as Adobe stock. I did not see the reason given by Adobe reviewer. What was the reason offered to you in the rejection notice? Read the materials suggested below. Best regards, JH
For your images to have commercial value, we expect them to be:
For more information on what makes a quality image, see The review process and Create better photos for Adobe Stock with 7 tips for success.
From looking at this, I would say it is because of noise - (artifacts/noise rejection):
If viewed at 100% you can see signs of noise - the 'grainy' appearance that this photo has.
I also think there is too much contrast.
I see from the metadata, that this is a scanned photo. So, this explains the noise. I am guessing you scanned this photo from a colour print/or negative - so it can be hard to get a good quality scan, especially to get accepted by Adobe. You'll have to be careful about your scanner settings.