They share the same CPU and GPU, you would probably be able to run C++ binaries compiled on either target, shaders will be translated to the same instructions. Both can use SSD as "extra" RAM, that is the biggest new feature of this generation.
The extra spice each SoC will hare are basically the same thing to accelerate audio and video code/encode and decompression.
There are no different paradigms. Even if PS5 is "better" for developers right now, it doesn't mean XSX will eat dirt in every area and every game.
Who said anything about “eating dirt” - not me....
The cpu and gpu may run the same code but that’s a superficial comparison point based on the apis in use (and PS5 has both Dx and it’s own apis) - but the use of SoC simulation and smartshift makes the optimisation of the code (and console development is all about optimisation) for PS5 different.
It’s optimised against a model in an entirely deterministic way while power budgeting is used to allow the gpu to be loaded up at the expense of cpu capability. That’s not the same as traditional console development or indeed the Xsex.
Xsex is using fixed clocks, discrete TDP for gpu and cpu and allowing power to vary. Sony is using unified power, and allowing power allocation to vary and in extremis clocks to vary too.
For the SSD obvioudly PS5 is half the latency and has its proprietary priority system. That enables the SSD to be integrated more closely into engine design. Xsex should achieve a similar, albeit less impactful solution.
Nevertmind the custom stuff, it’s not even a subtle difference between the two. The two are very different the closer to the metal one gets.