Do we know how many Su-57 are in service in the Russian Air Force? One or two?
In his summary review of the battles in Ukraine, Ah Yi (王世纯, aka Wang Shichun, who is often invited by Shi Lao to join him in talk shows) said that "the total number of 5th-gen airplanes in PLAAF is about 80 times of that in the RAF".
He also said that PLAAF has 1400 fighters in total while the RAF has only 400. The number of "special purpose airplanes" in PLAAF is about 10 times of that in the RAF.
His information on Russia's Su-57 fleet is probably just a bit out of date.
Russia had 4 Su-57s delivered as of late 2021 -- though I suppose depending on how one defines the readiness of those airframes, maybe he only considers 1-2 of those 4 Su-57s to actually be able of conducting any sort of missions.
I wouldn't read too much into it.