Resolution effect of sentinel-1 grdh product after pretreatment

In the process of soil moisture inversion using sentinel-1, I have doubts about the results of SAR processing.
After preprocessing sentinel-1 grdh product, I get 10m resolution SAR image. Compared with 10m resolution sentinel-2 optical image, there are great differences between them. I don’t know whether this difference is the difference between microwave and optical remote sensing imaging, or my preprocessing process is wrong?
The following is a comparison of microwave optical images:

Here are all the processes of preprocessing:

Sentinel-2 is sensitive to colors (and infra-red reflectance) while Sentinel-1 operates at larger wavelenghs. These microwaves are sensitive to physical surface characteristics, so it is not surprising that the images look different. Also, soil moisture inversion should be handled with care because artificial surfaces or surfaces which are covered by vegetation will not contain usable data on soil moisture.

Thank you for your reply.
Now I mainly want to confirm whether my SAR preprocessing result is correct.

The steps are alright and follow the known guidelines, yes.