PS4 might have gotten exclusive content but it seems as of right now a stable frame rate is exclusive to X1X and PC

You know how that optimization is gonna look like? They're gonna disable a couple of GPU and CPU heavy features. Look at what state they put it on the consoles, do you actually think they have any desire to really optimize something for console?

Well its not usual for games to improve performance post launch.

Its also worth noting the game mostly sticks to 30 fps on X1X. That tells me they did optimize for a console, the most powerful one.

No, that tells you it's not optimized at all because the only way to play it smoothly is to bruteforce it with hardware power.

It runs absolutely great on high end PCs btw. I guess that must've been the lead platform since it's perfectly optimized for high end hardware.

While the X1X has significantly more GPU power than other platforms, it's also using it to boost the resolution a good amount. The X1X has a little more CPU power, but not enough to make such a huge disparity there. Therefore other platforms should perform better with their much lower resolutions.

I think its just a poorly optimized game that was rushed out. Not the first time we've seen that.

Let me say this though: While the game is far from perfect, I've jumped from playing it on Xbox One X to Xbox One S a few times. I didn't really notice any performance issues--aside from (as I mentioned before) if you pause or press the home button the game becomes a slide show for several seconds.

I can't recommend it for $60 but it's not as bad as it seems.

Stuff like this is why I'm not a particular fan of mid-gen upgrades and kinda hope there's not a Switch Pro. There always seem to be some devs who inexplicably target the premium systems and put out games that run like a three-legged tortoise on the base system. Same thing happened with Hyrule Warriors on 3DS; fine on the new model, a slideshow on the base. 

Consoles aren't the lead platform, the PC was. - It has Ray Tracing.

The engine has multiple bottlenecks depending on scene, for consoles the CPU becomes a limiting factor rather rapidly thanks to the anemic performance of Jaguar.

The engine is actually rather good, just some of the options they are enforcing just isn't doing it justice... Like frame reconstruction with it's overhead when certain platforms have different forms of frame reconstruction which is hardware accelerated that is being unused.

More often than not, engines aren't entirely scrapped... It's a waste of time and money to do so, but re-engineered, overhauled and repurposed.

For example... Fallout 76 uses the creation engine which is derived from Gamebryo which in turn is derived from Net Immerse that came out in 1999.
The Call of Duty Engine has roots dating back to Quake 3 from 1999 and so does Valves Source Engine.
Battlefield V uses a derivative of Frostbite which stems from Bad Company in 2008...
Unreal Engine 4.0 still has some roots with Unreal Engine 1.0...

And the list goes on.

In short, you don't reinvent the wheel if you don't have to.

Indeed. Doom 2016  and Wolfenstein on Switch is a good example.

Or it's not optimized for the Xbox One X and the Xbox One X simply has the required baseline hardware required to run it semi-adequately.

Either way... Wait for the patches.

I think the ray tracing aspect was built for PC, but not the game entirely. Other games built with consoles in mind also have ray tracing, some get it unofficially patched in.

X1X has the same CPU and its not significantly faster. Yet that version does a much better job targeting 30 fps.

I don't think the engine is bad per se, QB did run at a solid 30 fps but that came with compromises.

Given people are waiting for patches to fix the performance, where is the performance problem coming from? Is the game in general just too demanding for the hardware or was it rushed?

I sense you're trying to use this as an example of console specs being too limited. I just see it as poorly optimized game if we feel patches can improve it. They didn't have MS money for this project so that might have meant less time to optimize.

There is Ray Tracing... And then there is Ray Tracing.
Control's implementation of Ray Tracing is a step forward of what we have seen prior, but even ignoring that, it's pushing some interesting technologies/effects that tend to be PC-only.
PC was certainly the lead platform, it's where it looks best, plays best.

The Xbox One X's CPU is significantly faster over the base consoles.
It has 43% more clockspeed than the base Playstation 4, 31% over the base Xbox One.

And then you have the programmable command processor which offloads some tasks typically done on the CPU, onto the GPU. - That isn't insignificant.

Those improvements don't just exist in a vacuum... And is probably one of the primary reasons why the Xbox One X version of the game is the definitive console version, the CPU.

Yeah, it's not an engine that is designed for 60fps, wide-open vista's like Frostbite, but for heavy scripting/storytelling and amazing effects. - For that, it actually does the job extremely well.

Bit of both probably.

If the hardware was more capable, the Xbox One, Playstation 4, Playstation 4 Pro and Xbox One X wouldn't be struggling. - Optimization plays a role, but so does hardware at the end of the day.

And then you have your money argument... - They had oodles of Money from Microsoft with Quantumn Break, that title still had a few issues, most got patched out, some still exist.