The major factions weren't fools. Obviously, they wouldn't allow talents to leave their own territories. Other than making more attractive offers, sealing off information and spreading false rumors were effective ways to retain talents.
Moreover, not everyone was like Lin Li, who didn't have any friends or family in this world. Even if the local factions didn't threaten a mage with his family members' lives, he would certainly consider this possibility. After all, a mage was still a human. As long as he could get enough money and fame from his hometown, he wouldn't try his luck at the Tower of Dusk.
But all this was different now. First, the Tower of Dusk had become the leader of almost the entire Breezy Plains, where all factions had submitted to it. Many of these factions had often spread false rumors in their own territories about the Tower of Dusk before, but none dared to do that now.