What about how the Infinity Gauntlet can do anything? Including terraforming.
Something about the gene-pool, something about average IQ in a population.
Something about how certain individuals in any population - especially those at the top of whatever social structure is in place - and how random removal of said certain individuals causes society to collapse.
Imagine if you had, like, something like a Time Stone, that could allow you to travel back in time to any population limit you decide.
What if you didn't just kill everyone? But enacted future population control?
Why is
killing first on the table?
Terraforming. Genetic engineering.
Do
literally anything.
With
unlimited power...Just kill people, I guess.