It's funny how you use establishment propaganda to justify the F-22's shortcomings, disregard any obvious counterpoint like the US could keep the F-16, F-15 lines running which were much older than the F-22 production. Yet at the end you reach the same conclusion as me.
The F-22 was a casualty of the early adopter problem.
Your spinning a narrative. A clear time line of it can be seen. With a number of late Cold War programs. Sea wolf class, Zumwalt class curtailed orders. It was viewed as a relic of the Cold War. The West curtailed and downsized the MIC significantly in the later half of the 1990s and early new millennium.
The US Congress and US DOD curtailed the F22 production to less than 200 units arguing that the type was unnecessary and that the new F35 would be better suited to the needs of the coming decades with Russian and Chinese F22 equivalents not expected until the 2030s.
As that happened the price point shot sky high. Congress imposed a limitation on F22 not found on previous fighter aircraft of the United States. That they couldn’t be sold for foreign military sale. This meant that only the USAF or other US DOD could buy it. F16 production continued for a significant period but a set date the USAF stopped buying them and new F16 models were foreign sales only. This allowed Lockheed Martin and the US government to maintain the F16 line in Texas until 2017 when the last one rolled off the line. However Lockheed Martin has built a new plant in South Carolina to continue building F16 because FMS are ongoing for F16.
F15E was the same story. After the USAF ended its buys Boeing kept the line alive because ROK, Israel, Saudi Arabia, UAE, Qatar and Singapore bought them. F15EX is a significantly improved F15E because it was built and paid for and manufactured in the intervening years by Boeing on their own dime and sold for profit via FMS to allied states.
Had F22 been offered to export a number of nations showed interest including Japan, Australia and Israel that likely would have kept the line warm well the USAF came back to it.
The problem was that the original 700+ F22 became 300+ F22 became 189 F22. That froze F22 technical development. You can only improve it so much as significant improvements aren’t possible without a huge cost due to trying to rebuild the aircraft itself. Modifications have to be inside the existing structure. The recent announcement of the F35 APG 35 radar is a perfect example. They can make that change because it’s still in production. They can modify older models to take it as they have the parts production up to a set point behind that point like with F22 the cost of the modification is extreme. You basically start building a new aircraft out of an old one.
As I've said before, I said the same thing about the Su-75. The Russians made a mock up of a plane, and are already talking optimistic about mass production and service induction dates. You yourself presumably can see the problems with that, and the counterrance wouldn't be that I or you are a B-21 or H-20 fanboy.
The Russians never operated their aviation fighter industry in any manor that was reflective of the the US. They farther have significantly worse economic and political conditions combined with rampant corruption and a weaker industrial base for essential systems.
That said T50 isn’t a mock-up it’s a series of prototypes. Closer to the US YF22, X35, or very early J20 flying demonstrators built from preexisting components lacking much if not all the critical mission components or trailing more primitive versions. The failure of the SU57 is that even the so called production models we have seen wouldn’t match what they are supposed to be going against due to stunted development and failures of the Russian MIC at every level. This is why many don’t call it a 5th Gen but rather use 4.5 or 4.75 or 4++++.
SU75 is a mock-up a 1:1 scale model that will never fly. The Russians claim to have a demonstrator under construction. But they also have a track record of making a lot of claims with little to show for it.
However almost none of this would be relevant to a comparison to emerging B21. A mock-up is a dummy. It’s the military equivalent to a concept car. The US military does build mockups all the time but they don’t roll them out at official ceremony they show them at arms shows. It’s an attention getter. Similar mockups are seen at the Zhuhai show in pavilions not hangers. Very rarely do you get mock ups the size of a bomber in the military as it’s very expensive.
The F-35 death spiral problem wasn't ever addressed. The MIC forcing the military to purchase F-35s in numbers sufficient to make the project viable again didn't address the fundamental problems the platform had that caused the forces to be wary of them.
You see here is the contradiction.
The F35 isn’t on a death spiral because it’s being order and procured in significant quantities.
Second because of how far along it is the “fundamental problems” have been solved. Much of the early on claims have been debunked or the most vocal critics whom were echoed have gone silent. The claims of its failure in a “dog fight” was debunked as it was operating with significantly less advanced FBW coding. The issue of its “slow speed” debunked as most fighter don’t use afterburners for very long anyway. The rest of the claims were either false due to early blocks that have since been updated unlocking more capabilities or were flagrantly false being pushed into the News cycle paid for by the likes of RT.
In fact this is actually reflective of the F22 and it’s issues. As many of the same characterizations were made of F22 in the early to mid 2000s. But where F35 is at the edge of 900 the F22 has a significantly smaller number of combat coded airframes. Which means that although F22 can be updated to use newer missiles, replace older systems, add new features the price per unit to do so is much higher. Which is why replacement is the new objective.