I would like to suggest to add a feature where if Edge is in dark theme, the scrollbar should also be in dark theme same as in File Explorer for Windows 10. It does not look good when the website and the whole browser is in dark theme but the scrollbar is in light theme.
Currently, when Edge is in Dark theme, the scrollbar is still in light theme.
When the File Explorer is in Dark theme, a Dark theme scrollbar is seen.
If you like this suggestion, then please send feedback about it through the in-app feedback tool (Alt+Shift+I) in Microsoft Edge to give it a +1 and to make it a part of Microsoft Edge in the future.