Tell me friend, what kind of training do you do? And have you tested yourself against other styles?
I like when someone says, "Anyone who has studied martial arts knows...." as if you know and feel you can speak for others.
All else being equal you think an expert in Tae Kwon Do would beat Muy Thai? I can tell you first hand that after a year in Jiu-Jitsu I was already beating guys who tooled me before and were more experienced in their discipline than in mine. I was able to submit D1 wrestlers simply because they didn't know submissions and always turned to their stomachs giving me their backs. Seasoned boxers were useless once on the ground -- and it was very easy to put them there. Like I mention before I easily submitted a golden glove boxer when just a blue-belt. A twenty year black-belt in Aikido wouldn't stand a chance against your typical bouncer who has been in a few rows. Judo, unless you walk around in a gi, isn't going to have much of a chance against a muy thai fighter. As far as TMA goes, they are the weakest of the bunch as Royce clearly showed in the early days of the UFC. All those katas and choreograph moves are worthless in a real fight. Royce, a 6' 170lb ecto easily submitted all his opponents who were far more experienced than he was. And you have the gall to say "Anyone who has studied martial arts for a somewhat extended period of time and is good knows that there is no one style that is superior to the other." Well, ask Rickson Gracie who has studied martial arts his whole life and tested himself in the street and in the ring. Rorion Gracie went from school to school challenging and beating other martial artist. He had an open challenge for $10,000 to anyone who could beat them. And there were many takers. I know. I was there. We'd make an appointment for the given day, shut the school down, the challenger would show up with their students, and their "master" would get their ass kicked every time. Every single time. It got to the point where the black belts from other styles had to fight a student before they would get a shot at Royce or Royler, both in their early twenties at the time. I participated in some of those and always won. I was just a beginner. A blue-belt. I just couldn't believe how ineffective those black-belts from other styles were that they were no match for a beginner in Jiu-Jitsu.
Don't speak for people that you know nothing about.
So again I put the question to you. What kind of martial arts training do you have and how have you tested yourself?
Your arrogance shows you know little about martial arts. I too have studied BJJ along with Kempo, Tae Kwon Do, Hapkido, and Krav Maga and can honestly say that if you were to ask any master of any discipline out there whether or not their style is "invincible" or "the best", the true masters will tell you that you cannot say one style is the best.
If BJJ is the best, why do others bother to train in any other style besides BJJ? Its because it is not. Every style has different things to offer, and if you cannot see that well that is your own belief.
Your examples are also flawed. Unless we can clone people and find a way to create exact skill levels of each discipline, there is no way that you can have a "controlled experiment" to test which art is superior. Who wins a fight is not dependent on "style" alone, but rather a combination of physical, mental, experience, and skill aspects. The better style doesn't win, its the better fighter. There is no way to gauge this.
Also just because someone is a black belt (or whatever belt), doesn't make them an expert, or a worthy fighting adversary. I'm sure even Black Belts of BJJ can get their asses kicked by a 300lb bouncer at a night club. Does that mean BJJ is worthless? Of course not.
Is BJJ a great art to learn? Yes. Can one say it is THE BEST, well no art can say that. If you truly believe that BJJ is superior to all (this coming from a BJJ practitioner myself), well I think you need to loosen your Tapout Beanie because its cutting circulation off to your brain.