They are offering the Su-57E with 177S engine at the time Su-57M with AL-51 is about to come out. They aren't dumb.
Russia has made a lot of whole new weapon systems since the Soviet collapse. Su-57, Yak-130, S-350, Buk-M3, Pantsir, Project 22350, 20380/5, 955A, 885M, Iskander, Kinzhal, Zircon, etc.
The problem is that whilst Russia can develop new weapons systems, they don't have the money available to buy them in reasonable quantities, so rely on exports. In addition, Russian military exports also have to compete with China products.
For example, aside from India as a potential Su-57 customer, everyone else is more likely to choose the F-35AE as a 5th gen stealth fighter because it is likely cheaper, better, has more technology transfer and also faces less political resistance from US strong-arming. So Su-57 production is stuck at minimum levels.
Arguably spending money to develop lots of new systems, but then not having the money to produce significant quantities is "dumb"
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Remember that Russia is literally 10x smaller than China in terms of population and GDP.
The manufacturing disparity is even greater.
So I think the Russians need to be far more strategic as to what they spend their money on.