Why does Linux still not have DSC support on driver 515?

Windows has been able to output 5120x1440@240hz for years now. Yet DSC STILL isn’t functional/enabled for Linux. I’ve seen multiple NVIDIA forum mods say “it is highly requested” or “it is enabled for monitors with single display connector” and yet it is still not here.

I cannot ditch Windows because NVIDIA refuses to pay attention to Linux driver support.