Well we do know that Odin hasn't sent in all his warriors all at once; players and the suggested npc lore characters have been sent before us, and in multiplayer worlds, some likely after; we are not the first, nor possibly last. We know from the runestones that some lore characters leave behind, that the warrior or player only exists in Valheim so long as they have the will to be there (a rudimentary but elegant explanation for saying you exist so long as you play, that in death in Valheim you can keep respawning so that you can continue to vanquish Odin's enemies). Of course some warriors will fail, some players will stop playing, so hence explaining why the current warrior player may only find ruined houses and no actual settlers.