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.
Please correct me if I'm wrong, but it seems Windows 11 is still broken when it comes to the legacy time-based CPU metrics. If the IdleTime workaround is not applied when using Windows 11, the legacy method will always report unrealistic low values, therefore being unreliable.