We don't use the standard description field in any of the screens and also have it hidden across all issue types under field configuration scheme for our project. It still shows up on boards though under issue detail view. It doesn't show up on issue view screen otherwise which is expected, but showing up as a non-editable field on issue detail view on boards is something not justifiable. The Atlassian link below says about description field :-
- Can be hidden, depending on the field configuration being used.
- Can't be deleted from the default layout configuration of the issue detail view.
https://confluence.atlassian.com/jirasoftwarecloud/configuring-the-issue-detail-view-764478043.html
Please let me know if that is expected or is there a way to hide it also on boards. Please note that since its not in the screens, so its also not on the board---> Configure---> Issue Detail view setting where you can remove it.