Seems awfully naive to me (or maybe
convenient) to ignore
AMD's anemic R&D expenditure in the ~3 years that preceded the release of Polaris + Zen + Vega, and the obvious impact it had on RTG's execution.
Most of us will agree that AMD's (specifically RTG's) marketing was terrible in the unnecessary hype they couldn't live up to (e.g. saying Polaris was coming "several months ahead" of nVidia's first FinFet GPUs, Vega being awfully late, saying Vega would clock above 1.7GHz, forcing Vega 56 down reviewers' throats at the last minute, and many others).
Regardless, AMD's general execution given the ~$240M/quarter R&D expenditure was great. Otherwise their shares obviously wouldn't have risen over 1500% during the last 2 years.
As for Sony's influence on AMD's GPU architectures.. there's some evidence that Sony's ICE has been calling the shots since AMD won the original PS4 .
The Liverpool GPU preceded AMD's own dGPUs in adopting 8 ACEs for improved Async performance and the TrueAudio DSPs. Neo's GPU preceded AMD's dGPUs and SoC iGPUs in adopting Rapid Packed Math.
And now there are sources/rumors claiming Navi is being driven by Sony again.
Sony doesn't compete in the PC space and neither do they want to, but they have always had a strong grasp over the architecture that went into their consoles (unlike Microsoft). The only time they didn't was with the PS3 but reportedly that was dual-Cell (or was it Cell-based GPU?) not performing as intended and RSX being a late adoption that didn't go well.
So given AMD's lack of resources for GPU development, it just seems logical to me that Sony's relationship with AMD is one where they don't compete in the same space and contribute towards the AMD's general GPU arch. Which AMD can then use in their own products but can't use in semi-customs for Sony's competition within a certain time period - which would explain why Scorpio doesn't have RPM CUs, for example.