Aviation is a numbers-oriented activity. Sure; we can more or less safely operate an aircraft by disregarding some of them, but if we intend to aviate with some degree of reliability and repeatability—not to mention professionalism—we need to do it precisely, which means using some metric against which to measure our performance and the airplane’s. In the physical world we inhabit, that most often means using numbers.
The good news is we have many different ways of measuring aviation’s various parameters. Altitude, for example, or airspeed. Angle of attack. Not only does the aircraft’s performance depend on numbers, so does our degree of risk. How else can we gauge our progress toward our destination, how much fuel is required and whether we’ll have the weather to land when we get there without numbers?
