This is important because not everything we add to a project is a task.
Now of course we can add general tasks, but the problem arises if a team member would “delete” any task by mistake.
A quick alternative of this can be:
1.) Normal users (not admins) are not allowed to delete a task
2.) Normal users can only mark a task as “completed” if it was assigned to them. If it is an “unassigned task” then only the admins can mark it as complete or delete it
Added as a suggestion here - Normal users (not admins) are not allowed to delete a task