Jira’s problem is that it’s effectively free-form, and there are no enforcements in place. You can have three teams - one using kanban with relative estimates, another using springs with story points, and a third using waterfall with time estimates - all in the same project, with the same workflows, and conflicting requirements. You have 3 different release fields, 2 are required, the third one is the one that your team are generating reports from.
That and its dog slow, of course.