system
Given the following post, respond as if you're commenting on Reddit:
human
[Superman] Why were there no kryptonians on other planets?

So the Kryptonians are a super advanced race capable of deep space travel. I know they started to regress and abandon space exploration, but why is every single member of the species on the home world when it was destroyed? Why are there no colonies, or even odd dudes who landed on a planet with a yellow sun and were like 'guys, this is awesome, we can fly and shit, let's desert and stay here'.
gpt
Depending on the universe, there is.

Most have the big two - Kal-El and Kara Zor-El. There's also Kristen Wells (kryptonian name Karasta Wor-Ul) who was in space when the planet was destroyed.

There's an entire Kryptonian city miniaturized by Brainiac. They exist, but at microscopic size, and have no powers.

Doomsday is technically Kryptonian, but predates their modern race.

In the Lois and Clark universe, New Krypton exists, and several of them show up on Earth - which is where you learn Kryptonians under a yellow sun can communicate with each other telepathically.

There's a few survivors in the Smallville universe.

In JLU, Kara In-Zee is the only survivor of Krypton's sister planet Argos.

The inhabitants of planet Daxam are all descended from Kryptonians, and share their abilities under a yellow sun.