Ok first off size doesn't matter when it comes to how much you can bench. So a 6'8" shouldn't automatically be able to bench 500.
There are 6'8" men that can bench over 500.
There is a LOT more then just a handful of people who can bench 500. Trust me, I'm on weightlifting forums quite often and it isn't as rare as you think. Do a bit of research and you'll find that there's a few groups of weight lifters.
There's the crossfitter, I honestly can't tell what is their purpose.
There's the body builder, they lift weights to make their body look as good as it can. They tend to do high reps with low weights to make muscles more visual.
There's the powerlifter, they don't care what they look like. They only care about lifting heavy. It is better for them to have as little fat as they can though because they are put into competitions based off of their weight class. Who's stronger. A 180 pound man that's all muscle or a 180 pound man with 15% body fat? The correct answer is the first man. These are the people who set all the records in weight lifting that are heard of the most. "Heaviest bench, squat, deadlift" Stuff like that.
Now there's the strongman. They are an unsual type compared to the other 3. They don't go for weight, body, or for anything else like that. They train so they can be strong in general. There are the ones lifting the anvils, they're the ones lifting logs, they're the ones that you want if your car gets stuck in the mud. They are a very unique type of weight lifter.
Now, neither of these types of weight lifters is better or worse then the other. Some might be hated more then the others (crossfitters) but they all train for different reasons so you can't truly compare them.
Personally I train as a powerlifter but I've taken a break so my numbers have gone down a bit.
If you can beat a massive biker then you gotta post a pic of yourself in that "what do you look like thread" viper lol.