Why is there so much air?

Air is all around. We cannot so called 'see' it but its effects are seen. However, Also it will not be proper to say that we cannot see it. The feeling of light all around us is because light getting tered by air. When we leave earth's atmosphere and experience light all around us, this feeling of light being all arouind is lost. May be we see light. through light tered by it. Light makes things visible but it itself is invisible.