This is a very astute and perceptive observation and, in thinking about this, you yourself can see that the value to the planet is not necessarily a given. And so, we can tell you unequivocally, that molds are not native species to the Earth. They were all introduced by the Extraterrestrial Alliance as an additional scourge, another life form that will compete with existing life, and cause many problems. It is like the fungi and some of the pathogenic organisms in the bacterial realm. All are a scourge, in one way or another, by attacking human directly, or things they depend on, for example the plant life, and animal life as well, that contributes to the ecosystem humans depend on for food, particularly the species that pollinate food crops, and the current scourge of microbes thinning their numbers and impairing function, as well as the many things that attack crops directly.
The molds are, for the most part, a minor annoyance, but they can be a source of great difficulty when they get too much of a foothold, and then can become a hazard to health. So requesting divine help for this is very much in keeping with the nature of the problem, to being outside the normal range of things humans need to develop the skill to manage on their own ideally, and to apply the needed wisdom to make good choices. There are many ways humans neglect themselves, as well as their belongings, and then will suffer a consequence. This is a part of learning to be a good steward, and to be planful and take precautions to preserve things and keep things orderly, and in good condition, to maximize their benefit, particularly when much has been sacrificed to gain the capability, whether it is a tool or a dwelling they rely on for shelter.
When there are interlopers present it is easier for the divine realm to assist, than if it is a normal part of the habitat, or a situation humans are expected to become proficient in adjusting or correcting, in order to make their way efficiently and successfully. So there is more divine realm can do about an invading organism at whatever scale. And so, requests for assistance here will be helpful.