The Su-57 is not as stealthy as the F-22 or the F-35, but the difference is tactically irrelevant. At best the difference is just a few times, like the difference between the F-16A and F-16C, at worst it's just 15-20 times, like the difference between F-15 and F-16.
When they say the Russians chose other parameters over stealth, what it means is the Russians could have made the jet even more stealthy, but they decided not to.
As per the Canadians, the RCS of the F-35 is 95% smaller than a tactical fighter. So, if we assume they were talking about 1m2 or 3m2, it can't be lower than that, it could actually be higher since the F/A-18C/D has a 3m2 frontal RCS, we get 0.05m2 or 0.15m2. The F-22 is said to be 0.3m2 and the Su-57 is 0.5m2. And these numbers are definitely not frontal RCS, the Canadians were very likely to have been speaking about average RCS, given the numbers we get. The Russians have also claimed the same, ie, all three jets are of the 0.1 and 1m2 RCS class. Flankers and Eagles are of the 20m2 class.
So the Su-57 is either 1.5 times bigger than the F-22 or 3 to 10 times bigger than the F-35, average RCS. None of the numbers being tactically relevant.
So when they say the F-22 looks like a marble, they are only talking about one aspect, but from other angles, including bad aspects for RCS, the average value would increase.
Plus the design, including stealth, was acceptable to the IAF.