Is anyone even using the full Jira featureset? People keep telling me that X doesn't have as many features as Jira, and I'm just genuinely trying to think of what those could possibly be to justify it? Like what does Jira do that Gitlab does not do that's absolutely vital?
Probably the biggest one vs Gitlab is cross-team functionality. Jira is very configurable that way, allowing you to share issues, epics, etc, in a very granular way. Gitlab was designed to tie things to repos directly. It does have some cross-linking, but it's clunky.
That's also the basis for the cross-org reporting that makes the MBA types happy. Yes, you can debate the usefulness, but that's who is signing the checks.
Using all features isn't uncommon for large companies with very heterogen team structures. And there aren't many alternatives that allow companies to tailor the software as well as Jira.
