The war in Ukraine demonstrates at least one important truth. While a modern weapon may look impressive on paper, it is worthless if the support system and training is not equally impressive. The sinking of the Moscow and the destruction of so many of the S3 and S4 missile radars by relatively low-tech weapons is a good example of this. Thus, the SU 57 may or may not fail not because Ukraine has better weapons, but depending on whether it can be deployed and maintained competently.
Competence is in short supply on both the Ukrainian and Russian sides.