in the end thats the reason 3rd party games were usualy better running on x360 as amd was able to provide much better capable gpu 1 year before nvidia (also they didnt have problem to deliver rt feature for ps5 and xsx chips even tough first rdna2 cards were debuting same time as consoles)
With PS5 and Series X, Sony and MS had been working with AMD consistently for many years. They've had many years of engagement with AMD's technology roadmaps - two whole previous generations in MS's case. They've had many years to work on semi custom branches to RDNA. Despite this, neither console has what you could consider a PC RDNA 2 part just dropped in.
PS5 is not actually "full" PC RDNA 2 - it's older - and has characteristics of RDNA 1 and RDNA 2. It's a mix of new and older parts of the roadmap. Sony and AMD had been working on this for years.
The Series X chip was apparently finished later than PS5, with both XBox and PC featuring full support for the new (at the time) DX12U feature set. Despite this, XSX is probably still a bit older than the first PC RDNA2 parts in terms of chip design, and carrying more RDNA 1 elements or layout or whatever. I think some of the die peeping experts said something like that at any rate.
All RDNA 2 types (PS5, XSX, PC) are ultimately based on the very similar RDNA 1, which predates consoles by more than a year.
Sony's situation with PS3 was very different than what's happened this gen.
What's more X360 GPU had unified shaders, when ATI PC gpus got these 2 years later... so nVidia deffinitely could do better with RSX and make it based on the GF 8000 series.
Not really.
The 360's GPU was based on an already in design GPU that didn't make it to the PC market for whatever reason. It was adapted and put into the 360, because MS could see it was the best available GPU for the 360.*
This isn't the same situation as G80. G80 was Nvidia's first unified shader architecture, and first DX10 product. It arrived along with DX 10 towards the end of 2006. Customisation and system integration takes time.
*What was right for MS to put into a console in 2005 might not necessarily be the right product for the PC in 2005. 360 didn't support DX10 either IIRC, unlike G80.
You are missing the point that Sony came to NVIDIA very very late in the design cycle. PS3 was supposed to rely on a second Cell CPU for graphics tasks. They realised too late it wasn't going to work and got NVIDIA on board. By that time there wasn't enough time to fully design a system around the Nvidia GPU.
The dual Cell idea was early on, IIRC, and I don't think it seriously went into development. Before RSX from Nvidia I think they were pursuing something like a Turbo Graphics Synthesiser from Toshiba.