Some my photos not accepted. Why?

When enlarged, the quality fails a bit - this is at 100%:

I guess they were taken on a smartphone?

You have to consider the contrast and white balance as well as well the composition.

Composition:
https://www.adobe.com/creativecloud/photography/discover/photo-composition.html

Quality issues?

If you are new to stock, you should consider these resources: https://helpx.adobe.com/stock/contributor/tutorials.html
Please read the contributor user manual for more information on Adobe stock contributions: https://helpx.adobe.com/stock/contributor/user-guide.html
See here for rejection reasons: https://helpx.adobe.com/stock/contributor/help/reasons-for-content-rejection.html
and especially quality and technical issues: https://helpx.adobe.com/stock/contributor/help/quality-and-technical-issues.html

I agree with the other comments. But with this one in particular, there is some "keystoning." The doors need to be straightened.

Some of these suffer from composition issues. In the first one, since the ceramic head is the main focal point, the empty glass vase should have been moved out of the way.

In the third image, if the moss-covered rock is the focal point, I would have just filled the frame with that interesting color and texture.

In the final image, the composition should have been perfectly centered and level.

Overexposed highlights. Another tip. Save your winter photos till the end of summer. You will have a better chance of them being seen. This is not a time of the year that buyers are looking for winter assets.