Isn't graph theory a mathematical theory about mathematical structures that can be ENTIRELY represented by symbolic structures WITHOUT any reference to graphical representations on a screen or piece of paper?

Then the mathematical representation might be an Association or a nested structure of Associations but have no information at all pertaining to a graphical representation such as vertex locations or their graphical style or the style of links - but only their mathematical graph properties.

Then there might be high level routines for the graphical representation of some common types of mathematical graphs. But this would not be expected to handle everything and so a user could use the mathematical representation to build up primitives for whatever graphical representation he wanted. The mathematical graph would be manipulated by Mathematica statements - but never through the graphical representation, which is derivative.

Wouldn't this make it much easier to work with mathematical graph theory, and make it much easier to tailor graphical representations from graphical primitives up rather than from a complicated structure down?

Szabolcs, please answer me frankly: is there any serious reason why to use Mathematica 12 for any kind of networks or graphs research?

From my point of view the Mathematica is going to be a more and more the magic black box tool, which is able to solve nearly everything, but surprisingly often not enough effectively and/or precisely.

Underdocumented functions are only one tip of problems iceberg.