Did you not read the slide? It's from De8auer testing of the BCLK external clock gen, using an ASUS Z690 Apex and 32GB of DDR5 6000MHz RAM... the CPU costs 1/3 that of the board, and in total makes up 10% of the cost of the platform it is installed on to get those results.
I stand corrected.
I saw that it was cinebench and remembered that GN saw a 1% difference between ddr4 and ddr5 when they looked into it. (Cinebench at least) What they did not do is extreme overclocking with any of the components.