Genuinely curious: How else would you coordinate a large software project? We have 7 teams of 5 working on the same platform and Jira is fine for what we're doing, but I've been at this almost two decades and I haven't used any of the alternatives.
Besides like trello asana redmine or the millions of less-complicated competitors? You literally have developers work on their own modules directly from the spec or work directly with the product owner. You track their work by looking at their commits. You check their progress by looking at how the preview build / staging looks. No overhead of having developers flesh out an entire issue/story (plus sub-issues) and then move it column-to-column across the entire Kanban board. Tracking sub-issues is like counting half-pennies instead of rounding up.
How did they develop code before Jira?