It's well known, but most probably he never used any extras of the OS (for example VMs etc). And then Task Manager works most often. Tho as I said above already, per Planet Earth math it's
IMPOSSIBLE having less CPU Usage while all cores have already more!!
Anyway... And I sent you already some time ago via email. In 7.42 for example I had only always this (without any loads):
View attachment 9244
And that's standard often in Task Manager when users use a bit deeper the OS, while all others still display totally correct.