Even if the recovery pills don't have the ability to increase the power of a person, it was still a lifesaver
In this world and perhaps in any other world, keeping one's life would always be more important than obtaining power
After all, what is the use of power if you couldn't keep your life? Power is useless to the dead
The recovery pills could be considered the pill of life and healing. Even if there are thousands of them in the market, it would never be enough
Since Rezen only asks for any form of resources as long as they contain mana, who wouldn't want to give him what he wants for the sake of what the other people want?
It was not only Daydream that scraped the resources that they have. Even other forces did the same as they don't want to miss out
Just imagine two mages fighting each other to death and right before they kill each other, one of them consumed a recovery pill that brought them back to their peak condition