And even more we all know, the purchase was more a political support towards Russia than a true operational need, even if it was a chance to get an insight into Russia's latest Flanker variant and to gain experience in using a TVC engine in service.
If that was true why does the PLAAF use the Su-35 in one of the most conflict ridden zones right next to Taiwan and Hainan island?
I think it served a similar purpose to the Sovremenny purchase. China needed some counter to US stealth fighters and it was the best thing available back then.
Any such ideas, China could or even would again purchase a Russian fighter and be it only for trial or as an aggressor is plain ridiculous and a desperate attempt to create or keep the impression as if Russia and the Su-57 are still in the same league.
I disagree. The Su-57 has better aerobatic performance than either the F-35 or the F-22. It has better kinematic performance than the F-35. I would definitively call it a 5+ generation aircraft once the Su-57M is in production.
The Su-57 airframe is lighter weight than the F-22's. Yet it has both more fuel and payload volume internally. It is clearly a way more advanced design using better construction techniques. The sensor suite is like a generation ahead. The design is only let down by engine performance. The AL-41 is a 4+ generation engine. Not a 5th generation engine. You could also argue that the cockpit and pilot interface is more rudimentary than that of the latest version of the F-35, but it is more advanced than the F-22's.
All the issues are supposed to be fixed with the Su-57M design. Which will make it the best 5th generation outside the J-20 which still has basically unknown specifications in a lot of parameters. And the Russians can build it for around $50 million USD per unit. That is like a fourth the price of the F-22. Half the price of an F-35.
This train has left the station since long and the fact that they are only showing a T-50 - in fact IMO pure embarrassment - and not even a real Su-57 or even the prototype with AL-51F makes it quite clear that Russia has finally lost touch.
My guess is the serial fighters are either in combat in Ukraine or being used for training pilots. And of course they would not fly an aircraft with the AL-51 outside Russia at this point in the development cycle. Last I heard it was still not certified for serial production.