Read the conclusion here...
This is a comparison video between War thunder vs rise of flight vs IL 2 Sturmovik vs DCS world.
In conclusion: We can separate the simulators in WWI airplanes, WWII airplanes and Modern Fighters, For the WWI airplanes Rise of Flight is the best, Also IL 2 Sturmovik with the Flying Circus but it is more expensive, for WWII IL 2 Sturmovik is the best, best price and dedicated to WWII, DCS also offers WWII airplanes that are very realistic but also more expensive. And Finally DCS World is the best on modern fighter jets and airplanes in general. War Thunder is fine to have a bit of fun but in my opinion it's not a simulator as the other I've mentioned.