FWIW I've heard DXVK actually can run on Windows, but you can't use it in AppX containers. Perhaps Intel bundling it with Ark's drivers would be a better option moving forward?
It's okay that those cards are reviewed according to their current state. They are pretty bad. But that doesn't mean the second or third generation of those cards has to be bad, when they remove the resizable bar requirement (so they can be used in older systems) and improve the drivers. DXVK would be a great route, but I doubt Intel can push this on a driver level - it would be more of a Steam or Windows thing.
I assume those cards will be a great option for Linux systems soon, where DXVK is the default anyway. It's good to have an alternative to AMD.
They'd have to add support for changing the base address register. The easy default is just mapping all the memory directly. It's a lot more programming work to transfer data when you only have a 256MB window to work with. No use sticking with a limit that PCIe hasn't had since 32-bit.
So requiring the “easy default” to be available means prohibiting any one with a system from ~2020 or earlier from upgrading to these GPUs.