It's not. ReactOS is a long-running project aiming at creating an open source OS that is fully Windows compatible so you can run Windows programs on it.
While it doesn't have telemetry and you can run it as a VM (arguably the better choice, given it's state), it is not Windows 10 by any stretch, and I guess it doesn't run the latest IE version (but I haven't tried it in ages)
While it doesn't have telemetry and you can run it as a VM (arguably the better choice, given it's state), it is not Windows 10 by any stretch, and I guess it doesn't run the latest IE version (but I haven't tried it in ages)