Creation is built on code over 20 years old at this point, and it shows
You can just as easily say the same thing about Unreal Engine, Frostbite, CryEngine, etc… all of these engines are built on decade(s) old code to some degree. The problem isn’t Creation Engine, it’s Bethesda. Unreal isn’t a magic bullet. The results if they used Unreal at this point would likely be worse, not better.