I think it's saying something like: what if it's impossible for a civilization to grow big enough or quick enough with our current technological path to make the bigger steps like harnessing the energy of our star and becoming space-faring. Perhaps instead there's some other path that looks more like nature which is why we can't detect it.

Like what if it was easier to master biology, create some kind of biologic computer distributed amongst all the living things on a planet, and load all the consciousnesses of the advanced beings onto that.