Not sure which YouTube told you 2400 ram get similar results as 32000 ram.... lol

In the beginning my motherboard xmp profile auto set it to 2666, so I manually changed it to 3200(profile 2). It just work cinebench scrored higher in both processor and graphic side (YouTube have alot evidence)....

For your info, APU really need higher ram speed. It will give better system respond and another graphic too. If you don't intend to play overclock, then why don't get Intel instead, they got build-it graphic too (weaker than Ryzen)

Second both Intel and Ryzen system has a function called dual channel memory. It's your own choice you want buy 1 stick of ram.... 4GBx2 work better than one stick 8GB  (YouTube have alot evidence)....