Because their resources were not completely non-renewable, after taking medicine for a period, they would regrow anew, but this period of time would be very long, and the low heat would definitely not give you enough time to prepare.
I mean, when the Cannibal Clan ran out of resources and attacked, they no longer had the grit, and most of the soldiers in the army were ordinary civilians, who would need weapons to complement their involvement in warfare, or they would be utterly weak and incapable.
Because ordinary people didn't have much ability, they had always relied entirely on their own physical labor to work and obtain food, entering a war was a very difficult event, and they even believed that they completely lacked the courage to join the army, which was already a rare feat.
