It's not a project used by anyone for production, or even testing environments. It's mostly just for shits and giggles at this point.

The problem is that there weren't enough developers able to help the project early on, and it's taken so long to make any kind of progress, that the targets they were trying to hit are long, long past. Even if it could be something that could 100% replicate an XP/Server 2003 system, I'm not sure how much utility that would have at this point, at least in a major production environment. Might be good for enthusiasts who still play older games and can't get a hold of an older copy of Windows. But even for production legacy systems, I can't see a business decision where they pick a relatively unknown OS like this to replace an XP stack instead of just modernizing. They might as well just stay on XP. And big enterprises don't choose projects like this for major deployments. They go with the tried and true solutions, regardless of cost or vendor lock-in. It's why "Wintel" has been a thing for 30 years, and why Oracle still exists.

I honestly don't think it will ever be a the drop-in replacement for Windows it aims to be. If it truly got to that point of completion, MS would sue them out of existence. They'd just tie them up in court making them prove it was pure blackbox development until they ran out of money and just folded.