AI-generated code still requires software engineers to build, test, debug, deploy, secure, monitor, be on-call, support, handle incidents, and so on. That's very expensive. It is much cheaper to pay a small monthly fee to a SaaS company.
And that's just atlassian.
Start adding stuff that costs many many many yearly salaries (special software for managing inventories and warehouses) it starts making sense to prototype alternatives internally.
I came to the conclusion that if it's not Teams/SharePoint or the moat is on the extreme legal complexity side (e.g. payrolls), you can at least think of building an alternative that is good enough without needing to be perfect.
All instances I remember seeing were neglected, not updated running on lowest amount of resources. Everyone in company nagging how slo it is but no one wanted to share budget to improve it.
So for me that experiment „it will be better and cheaper building our own JIRA” was already done. It is going to be cost center that no one will want to throw money at.