tbf... almost all of WinSXS is hardlinks, there is very little actual duplication. It's just that explorer doesn't understand that and reports it as duplication.
The next line of the output from the command you specified but which you didn't quote and that gives almost 5 GB on the machine in the example it is named "Shared with Windows"
"This value provides the size of files that are hard linked so that they appear both in the component store and in other locations (for the normal operation of Windows). This is included in the actual size, but shouldn’t be considered part of the component store overhead."
1 you specifically said "WinSXS is hardlinks", this is not true
2 still leaves up to 5GB of redundant garbage in WinSXS, things like multiple versions of random DLLs nobody ever uses, 360MB for ~11 versions of 'getting started' package consisting of same movie files, color calibration data for obscure scanners on bare minimal install etc
Turning drive compression omits this directory while happily compressing files in /system.
