I know the thread is old but look Dx12 was ported to win7 64x nice right? Microsoft lie on you time after time after time Blizzard made it for possible on wow i guess big part of china is on windows7 and they dont want to lose that community, for now its only wow that works on dx12 but more will come so lets cross fingers
Games use more RAM in Windows 7 compared to 8.1 and 10. DirectX 12 uses more GPU than CPU so if your processor is weak and the GPU is strong then games developed on DX12 ran better on Windows 10. In short if your hardware is weak Win8.1 if it is strong Win10.
But it is not the only game just search. In this same video and others I noticed this. This is not a problem for games that do not use up all of their RAM but it can be a problem in more demanding games.
I run GTAV, Warzone (which i deleted my account after reading on blizzard europe forums some political things), Tom Clancy’s Ghost Recon Breakpoint all pretty heavy games all smooth
I refuse to go any further with Win OS 8+ and above... so I couldn't give a vote. However, I just stick around with the Windows Server OS 2012 R2 and it's doing well for me. I find I have more control and options than Win 7 at times. I don't have any experience of Win 8 or more so I don't know what would be the difference.