Surely contributing to Wine and running their windows apps on Linux would yield better faster results than re-implement Windows from scratch. I don't quite see who the target audience is
I agree with you, an open-source OS that could run anything Windows-related would probably be preferable for the average user over switching to something completely new and hoping you can find a workaround or compatibility layer, simply because it's a lot more work. If ReactOS had been around and on par with Linux 20 years ago (oh gosh I'm that old...), I probably would've gone with that on the old PowerBook my grandma gave me rather than Ubuntu, just because I'd been using Windows. At the time, installing Ubuntu was, while the easiest way to get Linux, still not very easy, and I did bork the first hard drive. That said, I don't regret my decision, and I probably wouldn't ever go back to Windows, but I might still give ReactOS a try!
The value in Windows is no longer Windows. The cost of Windows license to a business is trivial. It's all the associated services. Office, teams, SharePoint, active directory, Outlook. And the ecosystems and support that exist for them all.
Any realistic business that tries to be competitive by not paying for Windows licenses and instead buying this, is utterly delusional.
Between 2007 and 2015, Russian ReactOS contributors representing the ReactOS Foundation made efforts at lobbying the Russian federal government. As of April 2019, these efforts have not yielded government support for ReactOS, and the Russia-based ReactOS Foundation has been dissolved since November 2015.
Was. Existed. Past tense. Your own links show that after its dissolution in 2015, that foundation was replaced with a registered German charity, so where are you getting "continues to be sponsored by Russia"? And even when it was around, all they succeeded in doing was showing off the project and asking for money. As far as I know, they failed at that. Even if they hadn't, that doesn't automatically damn ReactOS as some kind of KGB operation.