RADV: A Community Open-Source Effort To Get Vulkan Working On Radeon

[starshipeleven]

I would go one step further and say "there is a closed driver for the AMD SoC used in the ps4...", which is even more different.

Are you perhaps hinting at the fact that AMD isn't the developer of it but only provided the usual SDK as it is commonplace with embedded hardware?
Sony sure does look like they control the features they offer in the ps4 OS (there are some ps4-specific APIs), I doubt they have enslaved some AMD devs to make it.