What would you rather have for your bank account interest? Exponential growth or decay? Definitely exponential growth. Don't worry about your bank account's decay. College will take care of that for you.
Exponential functions help define things like population, bacterial growth, and virus spread. They are functions that help us look at how a cup of hot coffee cools or even the carbon dating of a material. Look, we know life is not all about straight lines.
What about logarithms? One famous logarithmic function was created by Richter, to help us determine the magnitude of earthquakes. Other logarithms help us use carbon dating to find how old material is.
Most of all, it is very hard to explain the universe without exponential and logarithmic functions. Think about it! Our universe is infinitely larger than one atom of one cell in our bodies. If we are comparing the mass of a cell phone to the mass of the moon, it's much easier to use a logarithmic scale.