For a civilization to develop over the long term, leaving its homeworld was an unavoidable step. A planet's resources were limited, and gathering all members of a civilization on a single planet also created enormous security risks. Therefore, after accumulating enough technology during the homeworld stage, every intelligent species with a normal capacity for thought had to venture into the stars—or some other realm. In short, they had to leave their cradle.
But the Erem Elves faced a desperate predicament: between their cradle and the nearest resupply point lay a distance vast enough to make any fledgling spacefaring civilization turn back. With their earliest aerospace technology, reaching it was utterly impossible. Unlike other civilizations, they could not find stepping stones and resource sites within their own stellar system, then slowly research various aerospace technologies with sufficient material and energy support. Nor could they find a neighboring-star outpost that they could reach within their lifetimes.
For a normal civilization to enter space, unless it was so gifted that it could develop deep-space travel technology and faster-than-light engines behind closed doors on its homeworld without making a single mistake, it would inevitably need to seek stepping stones within its original stellar system and use other suitably distant planets as bases for a series of studies. The initial accumulation of faster-than-light engine technology was accompanied by immense danger. Many experimental facilities containing tremendous power could not be built directly on the homeworld, and the fuel for the earliest faster-than-light engines could usually only be harvested on a large scale from uninhabitable gas giants. Even without these two conditions, there should at least be another sun near the original stellar system. It could not be too far away; at the very least, the first pioneers had to be able to reach it within a