I posted about this once before, and I think it holds true still. We on the forums, especially the upper 20% of us, are absolutely god awful at making assessments of the aircraft.
AKAK and JunkyII won't ever have any problems against any particular plane, because they've hit the point where they're able to fight the pilot more than the plane. By that, I mean they understand the underlying concepts of the fight, and can employ their full range of options as second nature, to such a vastly greater degree than their average opponent that there is very little he can do.
The average player, on the other hand, absolutely does not have this ability. They don't think in terms of angles and energy states, they think in terms of "oh crap, spitfires out turn me, better high tail it" or "damn that Brews got a lot of alt".
Most die before running out of fuel, so the range doesn't matter. Most die before getting any kind of chance to kill anything, so the ammunition doesn't matter. They're going to give up every shot imaginable, so no amount of armor would help, and any actual fragility doesn't matter. It has the three things that an average pilot needs the most:
Speed, and maneuverability, because for the most part the only tool in their kit is outperforming an opponent in one area of performance or another, and milking that for all its worth.
And small size, because for someone who WILL be shot at no matter what they do, being a small target is better than being able take a hit or two.
So yes, for a large portion of players, the Yak 3 is probably one of the best planes in the game.