Riky
Which RDNA2 features aren't being used yet and can you tell me what advantages they will provide?
I think he might be referring to things like VRS (Tier 2), Mesh Shaders and Sampler Feedback Streaming. Most of which have not yet been implemented in the current games.
Although I don't really see these features as what makes up RDNA 2, that would be more the architecture of the actual GPU. The PS5 offers similar functionality anyways. For example, Mesh Shaders are an API implementation, Primitive Shaders which the PS5 features will offer the same results. In fact, the RDNA 2 cards compile Mesh Shaders into Primitive Shaders in code and AMD have still been filing patents for Primitive Shaders within the past year.
We haven't got official confirmation for VRS on the Playstation 5, but according reliable leakers, developer comments and official patents it is very likely present on the PS5.
The PS5 does not feature sampler feedback streaming, although it is a cool performance saving feature. However I do remember RGT saying that developers were allowed to create their own similar functionality on the PS5, perhaps a variation of it will be available for it in the future for Playstation developers.
Once these features are fully embraced and utilised by developers I think we'll see some incredible things for both consoles. But to say they will offer the Series X some sort of big advantage over the PS5 is just not true.