I've seen videos of Skylake CPUs running in Coffee lake motherboards, supposedly. Doesn't make it true. I'd believe about 50% of what I saw on Youtube unless you can find concrete evidence by way of in depth, reputable review data on one of the major review sites like Tom's hardware, HardOCP, Techspot, etc., showing the same evidence.
Bottom line is Intel still has higher IPC than AMD. Nothing changes that. There could be a great many reasons why that user was having higher than normal CPU usage including issues with his Windows installation, lack of memory, too slow of memory, poor or buggy application installations, outdated or bad drivers. The list goes on and on. Core for core AMD cannot compete with Intel in most usage scenarios...