Why does being flat take more energy?
Galaxies are flat. You have no problem with that. The universe is flat.
https://www.space.com/34928-the-universe-is-flat-now-what.html
But you have a problem with the energy required to make a teeny weeny planet flat? 'Immense energy' compared to a universe being created? I've told round earthers a million times on this site, not to exaggerate.
The Galaxies are flat because they are spinning!!! But the "Flat Earth Theory" that the sun is spinning over the earth makes it stationary.
If the earth is stationary ( not spinning ) and is flat. then it is IMPOSSIBLE.
therefor the earth is a sphere and not a disk. You might say "if the earth is a sphere and spinning then why isn't it a disk? after all it is spinning!" Well that is waaaayyyy slower than a spinning galaxy.
The earth is actually slightly oblong due to its rotational force. This is consistent with the explanation of why galaxies are "flat".
Yes, this is consistent with my understanding of the Earth as an oblate spheroid. It is "fatter" along the equator, where the centrifugal force is largest. If we could, somehow, speed up the rotation of the Earth top match the rotation of the galaxy, then the centrifugal forces would become large enough to eclipse the molecular forces holding the Earth together, and the Earth would break apart into constituent molecules. These molecules would then collapse to form a disk shape due to collisions which removed (or averaged) radial velocities while still preserving azimuthal velocities (due to conservation of angular momentum).
It would be fascinating to simulate this.