Projects (and goals) have some serious conceptual problems. The biggest problem is that Projects are just one level above Epics.
But most organizations obviously don't use Jira the way Atlassian itself does. Most already have some sort of a hierarchy:
- As "spaces" were "projects" not so long ago, many still have that as their "project". There is not much benefit to switch to the new Projects-feature.
- Many further have created their own work item types that reflect a certain level between "project" and "epic". Atlassian even introduced "Initiative" as a work item type themselves. Epic is level 1, task is 0 und sub-task is -1, right? So we created level 2 ("phases") and level 3 ("subproject") types. Guess many other companies did the same.
Linking directly from "project" to work items on level 1 is an useless oversimplification. Nobody wants to have dozens to hundreds of epics directly connected to a project. To a product? Yes. To a team? Yes. To a goal? maybe. But not to a single project. Such a project has not much chance to suceed as their project managers have no overview. It is their job to break down a project into meaningful parts. Therefore you introduced levels a long time ago. And no, project managers won’t split projects into smaller, unrelated ones just to make your Project model work - they want to break them down at a lower level.
That's why they simply will not use your model. They will stay within their existing spaces, with their existing work item types.
Because of this: Please completely revise Projects from scratch.