Some resources are more scarce than others. If you have effectively infinite matter and energy, the scarce resources shift to things like conscious attention, l

Some resources are more scarce than others. If you have effectively infinite matter and energy, the scarce resources shift to things like conscious attention, low-entropy regions, and time-co-locality. Almost none of which are attained by invading and destroying another civilization. On the contrary, doing so actually would arguably evaporate resources you care about.