Cybertron is a giant energy-bee hive
Cybertronians are energy bees wearing fancy armor, Primus is a Queen bee and the planet is a hive built around them.
So Primus, giant multi-dimensional queen bee that they are pops into existence close to an energy-and-metal rich nebula.
Once Primus devours all the energy close to them, they use the materials they gathered to start sending out little energy-being spark-drones to collect more and bring it back to them since moving is so hard. Since they’re moving through an energy rich medium the sparks survive easily without guttering out.
They soon get to a point where their little drones are gathering more energy and materials than they can consume all at once so, in order to store it, they start building up the hive around Primus. The spark fields becoming a sort of ‘brood comb’ while they store excess energon in pools that are easy for the drones to access.
As the population of drones increases they need to bring back more and more energon and materials to keep up with hive creation. As they continue to consume the nebula around them they have to go further and further from the hive to get to more energon. This means they need to take fuel WITH them for the trip so they survive. Some of the little drones work out that if they take sheets of metal with them they can bring back MORE at once, making their jobs easier.
Over millions of years this evolves into scoops, containers, drills etc. as they start mining larger asteroids. Then they start making protective shells around themselves to keep themselves safe and keep them camoflaged.
Eventually these shells get so complex around the energy-bees that most species they meet don’t realise that the shell isn’t ‘them’ really. It’s a fancy suit of armor that they wear and control.
New cybertronians are still created in the ‘brood comb’ of the spark fields, but now they’re harvested immediately and given protective suits and sent out into the universe with the end goal of bringing more energon back to cybertron/the hive.
The hive gets built up so large around primus that it becomes near impossible to reach it, which slows down the production of new sparks as they take a long time to reach the surface.
This means that cybertronians are pretty much sexless drones of the hive, unable to produce young on their own. The colony ships that go out into space to populate new worlds are young mated queens who leave with a population of drones from the main hive to help them establish a new hive elsewhere.
