Ungovernable Galaxy

Basic logic will tell you that the larger an organization gets, the harder it is to manage and govern. Managing five people? Easy. Managing fifty? Harder.

Now apply that to an interstellar scale. With thousands of populated worlds, each containing billions of lifeforms, some with Blue and Orange Morality, and the galaxy becomes damn near impossible for a bureaucrat to keep track of and delegate the proper resources to every area.

While you can find good people out there in the galaxy, there will always be a Galactic Conqueror or a Horde of Alien Locusts lurking behind a nebula as a result of all the governmental cracks that one can slip through.

When a Galactic Superpower fails to do its job, this won't be far behind.

Examples of Ungovernable Galaxy include:

Comic Books

• The DCU. Until the 31st century, The Federation does not exist. Most species in the galaxy are left to fend for themselves against the Khunds, the Thangarians, the Gordanians, Brainiac, or Darkseid.
• The Marvel Universe isn't much better. The effectiveness of the Nova Corps is very much Depending on the Writer leaving multiple planets open to attack by the Kree, the Skrulls, Thanos, or Galactus. Their only real hope is that the Asgardians can spare some numbers.
• In Transformers, several characters make mention of Cybertron's colonies still having violence and murders compared to the pristine Cybertron. Issue #12 features Nautica reflecting on many alien cultures, several of which are genocidal zealots with Cybertronian diplomats being told essentially "Don't piss these guys off. Just smile and nod."

Fan Works

• The galaxy in There Was Once An Avenger From Krypton is a truly awful place. Gems might drop down any day with technology that no one can hope to match, should Thanos' forces show up, your planet is considered as good as dead, the Kree are willing to destroy whole planets because it makes their jobs easier and there's Vilgax who is considered just as, if not even more, dangerous than the Kree or Thanos. Also the Galra might be interested in visiting...

Film

• The Marvel Cinematic Universe follows its comic roots. Kree attacks are a common sighting, Ravagers and other lowlives prowl the spaceways, Eldritch Abominations are in hiding, and Thanos and the Black Order could drop down any day. The good guys are the Nova Corps but Police Are Useless and the Asgardians whose army is too small to be effective on a galactic scale. It's even implied that Alien Invasions are a mundane affair.
  • It's best shown in Avengers: Infinity War. None of the other major galactic players are shown to fight Thanos. The biggest contributions come from Thor and the Guardians of the Galaxy.
• Star Wars has to be the Trope Codifier. When Palpatine started his Evil Plan, Naboo was invaded and no one cared. It's mentioned that this is due to the Republic lacking a strong foothold in the Outer Rim, which was a factor in the Separatist movement, but even the Empire setting up a stronger presence there didn't do much to help this problem.
  • It got worse in the old Star Wars Legends timeline where the post-Empire era was marked by dozens of warlords seeking power and exploiting countless worlds.

Literature

• In The Hitchhiker's Guide to the Galaxy, the galaxy could very easily be governed but the bureaucrats and politicians are so inept, if not outright corrupt, that nothing gets done.

Live-Action TV

• Doctor Who features a similar set-up to Hitchhiker's Guide. The Time Lords could keep the peace but their heads are so far up their assess that they let chaos reign outside of Gallifrey. The local Space Police are so ridiculously inept that no one, from space mobsters to conquering species, takes them seriously and even they themselves seem to rely on the Doctor to enforce their laws.
• In Supergirl, there's no federation or republic to manage things, slavers and warlords fly around with impunity and wars are so common that a large amount of aliens have fled their ruined homes to come live on an Insignificant Little Blue Planet. It's implied that Krypton had a role in keeping the peace once and without it, everything fell apart.
• The Federation in Star Trek governs its part of the galaxy quite well. Trouble is, it's only 11% of the galaxy. Even the quadrant it operates in, the Alpha Quadrant, is divided into several states. The Delta Quadrant is a Crapsack World full of pirates, scavengers, tribalists, and the Borg.
  • By the time of Star Trek: Picard, the Romulan Star Empire collapsed without Romulus and the Federation, per Word of God not yet fully rebuilt from the Dominion War, didn't provide adequate support to prevent the Neutral Zone from collapsing. The Beta Quadrant is dominated by various wannabe Romulan warlords.

Video Games

• According to the Codex, barely 1% of the galaxy is explored, let alone governed, in Mass Effect.

Western Animation

• Police Are Useless in Ben 10. Hilariously so. Unless Ben is nearby, Vilgax or the Incurseans can take whatever planet they lay eyes on, unless it belongs to the other villain. Season 3 of Ben 10: Omniverse features the Plumbers constantly running after the Incurseans, consistently failing to ever leave a dent in their war machine.
• In Rick and Morty, the galaxy is full of galactic terrorists, sub-galactic dictators, alien mobs, Eldritch Abominations, and Rick who is probably more dangerous than all of them put together. The Federation does fight them; and aside from Rick, they seem quite good at it; but it's also a People's Republic of Tyranny that's mainly interested in wealth. Rick outright says in the fourth season finale that everyone in the galaxy is trying to take over the galaxy.