The Silver Empire and the Typhon Empire had each proposed a shelter plan that stood a chance of being realized under current technological level and production capacity. Whether it was the Sanctuary City Cluster or the Gondor shelter, both plans had distinct strengths as well as flaws that could not be ignored.
The Typhonians' Sanctuary City Cluster offered greater security, stronger disaster tolerance, and lower implementation costs. The shelter cities, spread across the continent and isolated from one another, were like "civilization backups" scattered throughout the world. Even if some shelters suffered accidents, civilization as a whole could endure as long as the Neural Network behind the city cluster did not completely collapse and at least a few shelters survived.
However, this plan required them to abandon more than half the world's population from the very beginning. And honestly... whether the smaller shelter cities could provide sufficiently strong protection against the Magic Tide was still unknown.
The Silver Empire's plan, on the other hand, could potentially save the entire world's population, while the scale of the Gondor shelter ensured that the entire barrier system's "output power" would be strong and reliable. Yet the plan's disaster tolerance was a fatal weakness. The Sentinel Towers operating at their limit were the shelter's greatest vulnerability—frankly, putting all their eggs in one basket in the face of a global catastrophe like the Magic Tide might be unavoidable, but the greatest problem was that the "basket" itself might not be very sturdy...
Not to mention that even if the Gondor shelter encountered no problems from beginning to end, how the enormous population relocated inside would endure until the shelter reopened was a century-old problem.
Many believed that the Magic Tide would last only a short time, that people merely needed to endure half a year