For a human society at it's second attempt at global industrialization it is doing remarkably well and needs to keep momentum.
They are wrong there are 2 main possibilities for what's been preserved. There is little advanced life and what little there is can't really get far fast and none seem to be near us or you can manipulate space and go faster and all that not that it matters and there is lot of advanced life even brainy moon sea life that used workers to build a steep mountain and to turn it into an antenna that can teleport to other star systems after billions of years of perfecting their minds and the mountain. What else would they do. Also this scale of energy use relative advancement scale only needs to get to a society level 1 and that level of power and they can be technologically be equivalent to a type 4 society so that scale is bs. This means that Dyson spheres are pointless and the reason we see what we do is natural territorial and with some deal of respect for planetary minds and emergent life nothing else.