The API Windows 10 provides to interact with cameras is totally different from that provided by libgphoto2, which Rapid Photo Downloader requires on Linux. So a Windows version of Rapid Photo Downloader would require being rewritten to use that API — or it would require using a lower level, older Windows API that was introduced with Windows Vista: Re: Linux: Rapid Photo Downloader faster than Windows 10?: PC Talk Forum: Digital Photography Review
AFAIK libgphoto2 barely works on Windows.
Then there are APIs to respond to events like disks being mounted & ejected.
All in all those two aspects are a world of work unless one is already up to speed with Windows programming.
On the plus side because Rapid Photo Downloader is written using Qt 5, at least the UI would be easy to port.
The main take away is: it’s a big job to port, which is why I didn’t do it already.