I will let you in on a little secret. One of my secret weapons when I shoot is this: kneepads. Technically I usually only wear one kneepad, on my dominant knee.
Kneepads let me drop to one knee quickly when doing portraiture and modeling shots. They also let you quickly change your point of view when shooting anything (like nature photography). If you are less likely to get lower because it’s uncomfortable, or you are concerned you will wear out your knee over time, a kneepad is a quick remedy. Taking pictures from your normal standing position is boring – it’s good to change things up to make photos more interesting. Getting lower is a must in portraiture (e.g. full body shots).
If you say you don’t need kneepads, that’s fine – but if you find yourself not bothering to get low, then ask yourself why not.