You have almost 6 orders of magnitude available to make the comparison with whatever transaction method you prefer.

You could fly gold bars around in small planes, and it would still be more efficient than Bitcoin.

What if we have to account for all the bankers and their houses and cars and everything they need to live to continue our current financial order? People focus on simple math, but bitcoin doesnt need all the people to sign the docs and keep track of them, that's the catch.

Bitcoin isn't replacing any of them, so it's a moot point. If someone wants to buy real estate using bitcoin they are still probably going to use a realtor (or at the very least a lawyer) and they still probably need a mortgage, title insurance, and home insurance. If a company wants to go public, there is still going to be an army of i-bankers involved, even in a bitcoin denominated world.

The banking sector exists for a reason. There are certainly parts of it that are superfluous and excessive, but someone somewhere is willingly paying for that excess, and that won't change under a bitcoin regime. And I personally think that most of the excess is due to excessive speculative activity in our financial system, and if anything, bitcoin seems like it will make that part worse.