HDR is just a scam. It's essentially automated brightness and contrast controls that is terribly done. I've seen HDR on brand new displays running HDR-capable everything and it just looks like someone can't figure out how to set their monitor up correctly. It's a buzzword created for crap technology that makes people want to spend more on essentially the same trash.
And as for scaling, look up FSR.
Windows is 100% obsolete and anyone who disagrees is just looking for excuses.