Question

how are plants useful to all of us other than food

Answer 1

because we get food from plants so if plants will be there we will get food

Answer 2

Plants make oxygenOne of the materials that plants produce as they make food is oxygen gas.  This oxygen gas, which is an important part of the air, is the gas that plants and animals must have in order to stay alive.  When people breathe, it is the oxygen that we take out of the air to keep our cells and bodies alive.  All of the oxygen available for living organisms comes from plants.Plants provide habitats for animalsPlants are the primary habitat for thousands of other organisms.  Animals live in, on, or under plants.  Plants provide shelter and safety for animals.  Plants also provide a place for animals to find other food.  As a habitat, plants alter the climate.  On a small scale, plants provide shade, help moderate the temperature, and protect animals from the wind.  On a larger scale, such as in tropical rainforests, plants actually change the rainfall patterns over large areas of the earth's surface.

Plants help make and preserve soil in the forest and the prairie, the roots of plants help hold the soil together.  This reduces erosion and helps conserve the soil.  Plants also help make soil.  Soil is made up of lots of particles of rocks which are broken down into very small pieces.  When plants die, their decomposed remains are added to the soil.  This helps to make the soil rich with nutrients.