Why is my memory always at least 5Gb full out of 8Gb since I created my first WSL2 instance?

Simple question, I created a WSL2 instance on 8Gb of RAP laptop and immediately saw the memory usage increase to 6Gb with no process taking that much memory (including all process combined) :

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Obviously this sounds like to be a VM issue.

I started by trying to delete the VM instance, and even went to try to disable hyperV, but the memory usage problem when no foreground application is running persists.