How do they get to be a G.C.?? (General Contractor)

In the state of TX to be a (G.C.) General Contractor you do not need a license or to prove to anyone you have any clue what you are doing.
Only some trades (sub-contractors) are required to have licenses. i.e. plumbers, electricians, h.v.a.c. installers/techs, and most engineers.
Contractors sometimes (most) have to register with a city and provide proof of insurance (usually 1million dollars general liability) and some make you provide a bond.
All licensed trades will pull their permits under that contractors General Permit on projects. Ultimately making him/her responsible for those trades actions. (note: do not pull the permit yourself, you want a G.C. to be liable)
Contractors essentially are there to negotiate what each trade does. i.e. budget, scope, timelines. And then contracts (signs a legal document as to what is going to progress in the agreement) that trade for that task within that projects total scope. That’s it. Of course, knowing quality trades helps the contractor. Having a solid idea of what it takes to accomplish the task in which he has taken on, and also the ability to communicate clearly with both the project owners (or designers/architects/permit departments/nosey neighbors/etc) as well as all of the trades in order to get the idea’s from 1 (or several) persons dreams and into a seamless reality.

(or maintaining the illusion of seamlessness in a storm of utter chaos all while managing to compete the task at hand.)

how is it done?

Numbers don’t lie and facts really matter, its the reason I can be so confident it the things I say. Codes and stamps regulate safety, customers pick out the fixtures and color of paints, style of flooring and grade of cabinets out of my control.
My job is all about knowing.
What things cost.
How they are done.
Who to hire.
Who to trust.
How long till complete.
Manage all paperwork.
Qualifying trades.
Knowing if things are being done correctly.
Getting an extra box of tile cause we came up short.
Replacing trade who’s truck “keeps breaking down.”
Its pretty easy once you have the skill and knowledge on how things work. Sure it takes a lot of years, but it can’t be taken away or lost on a bad deal. Its value is real.