How I think it all works

I'm writing this as an intuitive so this is not your average point of view. Whether it is useful or not to you is up to you. But I would recommend thinking about this as science fiction at least at first.

The structure of Order in this Galaxy-

First of all I think that there are trillions of human like beings or more in this galaxy on thousands or more planets.
You might ask "Why don't they visit us?"
My answer, "They do. But they have no reason to destroy this very quaint and very entertaining place."
Then you might ask, "Who governs this galaxy?"
My answer, "It isn't humans. Humans are not known for their intelligence among Galactic races of intelligent beings. They are known to be survivors and to adapt to wherever they go and colonize. But if you took the average intelligent being in the galaxy and asked them what they thought of humans throughout the galaxy and not just here on earth they might talk about us like we were technological and capable of traveling through the universe but generally unsuited for contact with other civilized races generally because we are too animalistic and hotheads(we kill things we don't like and sometimes eat them). This is considered barbaric and unsophisticated. I think I agree with them in this.

Besides, as far as I could figure out the kinds of beings who actually created the galaxy actually run it and they are not even physical beings as you know them. They are more like stars and Nebula or even like Black holes in composition. And even that doesn't describe properly what they are. They are just so incredibly long lived and can't even really die except from boredom that anyone who even considers messing with them from any physical race sort of is struck by lightning or plasma and is no more or just disappears. So there is order in the galaxy because these beings I call "The Creators" are the order here. One of the things they are very big on in their sense of order is that no hostile groups are allowed to meet each other and have wars, especially here in the solar system. This is because a surface thermonuclear war happened here and blew up one of the planets and it is now the Asteroid Belt. So we aren't allowed to meet any other races formally because they don't want another planet destroyed by a thermonuclear war. So they control Time so this cannot happen again and prevent any formal contact between us and the nearest civilized planet formally. They also won't let any planet make war on us and now they won't let us use nuclear weapons anymore beyond a certain megatonnage. So probably the most that would be allowed to blow up would be a city and I'm not even sure that would be allowed after what happened on 9-11.

So though it would be allowed for us to self destruct we will not be allowed to nuke ourselves out of existence and take the planet with us. It would have to be ecological if we all go extinct. And even then it is more likely that we would just return to something like the stone age and start over rather than all die off. This is my experience. I hope it is useful to you.