Windows OS does not provide a GUI to dissociate file type extensions. If you need to remove file association, you can use Unassociate File Types utility.

OpenWith Enhanced replaces this basic tool with one that tells you which programs are the best options, lets you remove associations, and even change icons for specific file types.

Upon opening it with Notepad or any similar editor like Visual Studio Code or Sublime Text, you will see alike to files types and their associations with the programs.

MSFT says this is to prevent apps hijacking file type associations. This would be good, except that Windows itself doesn't allow users to change it.

For quite some time, users have been reporting an inconsistent bug in Windows 10 that prevents them from changing the default program that are associated with a file type.