On doubling the resources, I think that falls into the “obvious, but wrong, answers contain the word ‘just’”.

let’s say you double the resources. without being specific, you just doubled light and the mass of the sun and the mass of the planet and killed everyone.

ok, let’s say you get more specific, drinkable water. double it. in place? there goes every pipe and reservoir on the planet.

plant nutrients? now the concentrations could be toxic for the plants and now they’re dead.

double the asteroid belts? a lot of these species are space faring, after all.

each species and planet would need a custom solution, and that takes work. In addition, the main issue isn’t the availability of resources, it’s how they’re allocated.

just doubling all the resources could end all life in the universe.