SAM have an efficacy rate of 50 to 70% at best. Patriots have been found to intercept upto 70-80% of targets which is pretty good. Intercepting a missile is a tall order mainly bcz their low RCS allows for very little response time. Point defense system is the best option for incoming missiles.
My point is that nobody can claim Russian/Chinese/American as being superior to each other. The only way to find that out be a actual war. Which I hope never happens. Claiming that USA has better air defence systems is simply not true. The same can be said to those who claim Russian as superior. The S-400 is only superior on paper. That is why so many US allies want to buy them. Including Saudi Arabia, Turkey, Egypt. Even Greece bought the S-300.
In term of Performance, S-300/S-400 were more comparable to Aegis Defence System fielded by US Navy. The Scale, Range of Engagement, The Capability of Using Flexible choice of Interceptor Missile according to Target, etc.
The Russian system also protected by Close in Weapon System component in form of Pantshir. making Russian SAM Site that employ S-300/S-400 have similiar Deterence or Capabilities to Aegis equiped Warship
That makes, (on Paper) S-400 were way superior system than Patriot and anything that the west has to offer. Which means that currently Russia has the best air defence systems (on Paper) in the world.