answering here because of nesting limit:
A computer is a combination of many vastly different things whereas a SBD is just a collection of steem.
SBD is not just a collection of STEEM, oh no.
- SBD is a smart contract
- SBD would not be possible without price feed
- price feed would not be possible without witnesses
- all of these would not be possible without a concept of blockchain, DPOS and many more
Calling a collection of steem "dollars" is erroneous and misleading to those who don't understand what they really are.
most money of the world are debt, but no one use this term. Dollar is already abstract concept (would you be able to explain what is a dollar to someone from stoneage?). SBD is the easiest way to understand on entire steemit. You do not need to know how engine works, to drive a car.
The other things you mention are not part of the SBD itself. They're auxiliary support components. The US Dollars we use today depend upon a vast array of supporting systems, people, and devices like the Federal Reserve, Treasury, Secret Service, bonds, banknote printers, etc. Auxillary support components like those are essential to the function of the Dollar but they are not part of dollars themselves.