I literally just told you. Read the post above the one you quoted.
Sorry, I did not notice that "this" was a shortcut.
I am using a 1920x1080 screen, and used this github page for my icons.
From your screenshot in your original post, it looks like the scaling of your display is not set to 100% (maybe around 125% ?), since your taskbar is 72 pixels high - I think 48 is default at 1920x1080, 100% (no scaling) Have you tried to set your resolution to 100% (no scaling) to see what it looks like?
Using custom made iconpacks like that one, are known to modify your system files and cause a variety of issues. These modifications are not always resored even if you should choose to uninstall them. The icon pack you have linked to in your post #23 is not for Windows 11, and most likely anyone installing that under Windows 11 will encounter issues. I have downloaded the pack to be sure, and it was created on April 8, 2020. Windows 11 was released October 5, 2021 (18 months later).
Maybe someone can make this work on Windows 11, but it certainly isn't recommended. (I still see no link to the tutorial you have folloed, if I haven't missed the link to that one too?) I have to read that tutorial to see what has been modified and what other tools they have used.

- What you can try based on the information you have provided so far is: Follow this tutorial to restore missing or corrupted system files (including system icons) : System File Checker
- Set the scaling of your screen to 100% and apply the theme.