Russia's Low Accountability Light Fighter
hushkit.substack.com
Trying to look at the article from a neutral position, some claims are reasonable and some aren't:
1. Russia is obviously struggling to field new systems. The USSR always had a more limited GDP and after the break-up of the USSR the situation is obviously more difficult for Russia, with the current war further draining resources (and limiting export opportunities to support the industrial base). So it is difficult to sustain an ability to field new systems in large numbers.
2. "Plasma stealth" claims were always closer to what you'd read in 'Popular Mechanics'. Judging the credibility of U.S. aerospace companies based on what is published in Popular Mechanics would be unreasonable.
3. Failure of the initial FGFA isn't that surprising, especially if one looks at the history of international joint-development projects (e.g. in Europe). It doesn't even necessarily reflect significantly on the design itself.
4. The failure to field a single engine type after the Mig-23/Su-17 is a conscious doctrinal decision. The proposals for single engine types were developed by industry (generally unsolicited). The question is whether VKS doctrine continues to forbid the use of single-engine types, not whether they could field one if they wanted to. The aversion to single-engine designs at a doctrinal level would seem to count against the success of the Su-75... but the fielding of the S-70 suggests that at least an unmanned CCA is a possibility.
5. Russia with its reduced economic base is very interested in finding export customers and regaining some prestige to support those exports. China has a huge economic base and GDP in comparison and is interested in creating deterrence through uncertainty (in a Cold War like situation). Neither is going to provide particularly accurate information about what is actually going on.
One could also question whether any modern fighter has been rolled out "at scale, on schedule, and without compromise" (at the author puts it).
So some of the observations (economic base, doctrinal aversion to single-engine designs) are fair, but a lot of the other observations could apply equally well to any other country.