It is annoying to use, because every action takes seconds to complete. Nothing in Jira ever feels snappy. Everything feels delayed. Things are hard to find in the jungle of clickable things in the UI. Things seem to be put in places, where I would not intuitively look for them. That is only the UI. There are also bugs lurking in the depth, which will probably never be fixed. Recently I've seen a coworker edit a story description and suddenly the browser showed an API JSON response, with the whole Jira page gone and only that browser native JSON display. Recently I've tried to sort task on my to-do tasks list on the sprint board, but could not arrange them how I wanted, because one of the tasks was a subtask of a task, which was not assigned to me and thus not visible ion my "only my tasks" filter. You have to make all tasks visible, then search for the supertask and then arrange that to be higher in the list, then navigate back to only your own tasks and the subtask will have moved up. Things that take a second with a reasonable UI take 10 or more seconds in Jira. It is a catastrophe of UI design.
