This is absolutely true and TechPowerUp's counter control utility does fix the issue for me as well on i9 10900K system. My Cinebench score improved by almost 1000 points after resetting counters.
Before resetting counters on counter control:
After resetting counters on counter control:
So yes, the fix does work, absolutely. Anyone here saying otherwise has clearly not tried it themselves, or owns a CPU that's not affected (likely an AMD CPU). I also noticed when testing that before I reset the counters, Defender used 2% of my CPU during Cinebench run. After I reset the counters, Defender only used 0.1% of the CPU during the Cinebench run. So quite clearly it is Defender causing the issue and this fix does indeed fix the aforementioned problem.
Quite pathetic that Microsoft and Intel haven't fixed this issue by now. This bug must've been there for quite long time before it was even found. Light users probably have never noticed it, but under heavy stress its been noticeable for me on many Intel based systems. Its why I kept using ESET, but after this fix I've been using Defender again and its now actually very light.
You can download counter control from here