It's not the object being portrayed that is art, but the way the object is portrayed.
Example:
who here would say "That's art" When viewing a spectacular sunset. ?
not many , if any.
The handy work of God (popular belief anyway , or nature)
However, view a portrat of a spectacular sunset? , and most will say, "Thats art"
As to why some art reaches the level of world renown art? it's because of the "masses phenomenon" effect
You know , when people join in on something just so they are not left out.
We view certain planes and other objects ( as well as the Computer generated replicas) created as being works of art.
But there again It is just a plane, or a car or whatever. What sets some planes apart from others is the craftmanship of the
architects engineers and builders of the plane. All looking through the critical eye of the artist - following the rules of form and functionality
of the object being built.
If it a plane, ..gotta have wings, Well throw in some scientist in the mix, bend the laws of physics (yet still following form and function)
and they come up with the delta wing, screw it make the whole of the aircraft a wing, right? Who says it has to look traditional.
thus XH558 and Concorde ,, Space Shuttle ect ect ect.
But , This is my opinion,.... others have theirs just the same.