To begin I would just want to let you know that if you came here expecting one to be much better than the other, you are going to be disappointed.
GPU & Resolution
Aka 12.1TF vs 10.3TF. This is the single most stupid thing to argue about, why? Not because its just a 14%/17% performance different, or not even because with the PS5 higher GPU clock means there are things in the GPU that it would actually be faster at doing or be able to do more of than the XSX GPU; but because a lot of people are using an antiquated way measuring performance. A way that devs no longer use.
This is not like 2013(PS4 vs XB1)/ 2016(PS4pro) & 2017(XB1X), where a 40% advantage in performance pretty much translated to a 40% difference in resolution. even ignoring that in both cases there was also sizeable deference in memory bandwidth and in one case (XB1X vs PS4pro), + amount.
No, its the age of variable resolutions. And understanding this would make you understand how stupid it is arguing about the GPU. Both consoles are going to be running native 4K at the exact same FPS, same geometry, same texture detail, same everything. How is that possible you ask? Simple, because devs would have the same rez target or both and the same framerate, but what would be scaled would be the resolution.
TLDR? It's a simple case of resolution scaling. Its not about one console running all the time at 2160p and the other at 2052p. Its that the XSX would hit that 2160p native rez ~95% of the time and scale down rez as needed for the other 5% of the time and the PS5 would hit that native 2160p rez ~85% of the time and scale down rez as needed for the other 15% of the time.
And what makes this even crazier? Is that the floor is really high this time around. We aren't talking about 2160p vs 1440p (~50% difference) or 1080p vs 900p (~50%), we are talking about a maximum floor of 1800p - 2052p vs 2160p (~30% - ~16% difference respectively). When pushing that many pixels, it becomes really really hard to tell the difference between something running at native 2160p and something running at 2052p or even 1800p.
I could also be talking about things like cache scrubber and coherency engines...etc... but let's just keep this simple and to what people would actually see.
SSD
This is another bone of contention apparently. Yes, no argument here, the PS5 SSD is over twice as fast. But would it really make a substantial difference? No. No, it would not. Why? diminishing returns. Its one thing comparing 5500MB/s SSD to a 55MB/s HDD, yup, that one is easy. You are getting 100x the performance. But comparing a 5500MB/s SSD (PS5) to a 2400MB/s SSD (XSX), just nets you ~2x the performance.
Don't et me wrong, I am not saying the PS5 SSD is just a waste, but rather that where it would make a difference isn't really where most think. It would make the PS5 easier to develop for. And in turn, easier to optimize for. This has a lot to do with data streaming. It would also make it possible for the PS5 to have a little more RAM available to devs than the XSX (depending on how sony decides to implement this that is).
Basically, whatever the XSX can do with its SSD, be it stream in more data into RAM, or load games faster... the PS5 would be able to do it better. But this wouldn't matter because the XSX can already move a respectable amount of data. Now if we were talking about 24GB of RAM consoles and 300GB sized games, then the faster SSD in the PS5 would wipe the floor with the XSX SSD. But we are talking 16GB of RAM consoles, more specifically ~13.5GB - 14GB of RAM consoles... .. even more specifically, around ~5GB - 8GB of RAM cache consoles lol. Yes... ~5GB-8GB. That's how much RAM these SSDs really need to worry about feeding because that's where the CPU and GPU Native heaps pull their new data from.
The PS5 should load into games around 1 or 2 seconds faster though; so its at least got that going for itself. For all that is worth...
That's it, those are the two main areas that make these consoles different but as you can see makes them still very similar. I hope that helps.
