Replace ‘first in their galaxy’ with ‘first in their own past light-cone’ and you not only remove the assumption that travel between galaxies is difficult, but also explain the fact that we haven’t observed any. If we assume they travel at near-light speeds and consume anything they can reach then any point from which they could be observed has already been consumed.
Replace ‘first in their galaxy’ with ‘first in their own past light-cone’ and you not only remove the assumption that travel between galaxies is difficult, but also explain the fact that we haven’t observed any. If we assume they travel at near-light speeds and consume anything they can reach then any point from which they could be observed has already been consumed.