But jira isn't the problem that's being solved - a person hired full time would be a project manager, who in the absence of jira, would solve the project manage

But jira isn't the problem that's being solved - a person hired full time would be a project manager, who in the absence of jira, would solve the project management problem with different tools. Jira is not perfect. But the atlassian suite as a whole, with integration between CI, PM and version control, is quite powerful and more than adequate in many cases. That said, boy have I seen it used terribly. It's double edged for sure.