The game is subjective there is little real life combat use of any of these systems, tests can show any thing people want them to show. When used in combat it seems western equipment/ training comes out ahead. Russian and Chinese equipment is mostly bought by poor nations Most of the gulf states buy western equipment. Why? ( If there after kick backs I am sure The Chinese or the Russians would pay more than Western companies.) So it must be better equipment. I know the Russian fans boys will disagree. But why would counties that have lots of money buy inferior military hardware. I know their military professionals may not be on par with there western counterparts but I am sure they are more knowledgeable than most of the computer chair generals and admirals that play this game. No offense to any active or retired military .
As others have mentioned, there's a lot more going on with these systems than you're considering. First, the Russians have made SAM development a national priority, unlike the west, and have prioritized anti-aircraft over ABM for their SAM systems. As a result, their SAM systems are typically more capable systems than their western counterparts against aircraft.
Furthermore, these aren't cheap by any means. A S-400 or S-300PMU2 costs somewhere north of $400 million, and if you're paying that kind of money, you expect a top-of-the-line system, and yet Iran, the Russian AD forces, and China are all trying very hard to get them. This isn't exactly the signature of a poor system.
Compounding this, think about the SAMs that the west has actually faced. The latest system was the S-200, in Libya, and captured I-HAWKs in Iraq. For less advanced systems, we've also faced S-125 Neva, and S-75F Dvina. The very latest systems were made in 1971 (I-HAWK) or in 1967 (S-200). This means that we've never actually faced an S-300 derivative, even the original, and it's widely considered to be a vastly superior system to any of the ones that I've mentioned.