I saw mention of indoor vs outdoors. Indoors there may be reason to defoliate lower parts of the plant depending on your light source.
Many of the lower power light sources do not have very good penetration to the bottom of the plants, with the goldilocks zone being a foot or two from the top of the plant.
In cases like that removing some of the crap at the bottom creates better airflow (important as it brings fresh CO2 to the leaves), prevents damp spots above the container, and more importantly stops the plant from developing in areas not covered by enough light.
if you stretch the fingers on your one hand straight and then cup them upwards while keeping them straight, you will see a bowl shape, If you have the space to train your plants in the shape your fingers are in, I.e. like a funnel with the centre open. Light can get through to the bottom, and defoliating becomes absolutely redundant.
There are no universal rules to this shit though, a grow in a small tent needs to be treated differently from a larger tent or room and even more so when grown outdoors, where you have all the light, and airflow you could want.
Just another thought, people say the plant bounces back after pruning, but wouldn't it be bigger if it grew the new foliage in addition to what you had, rather than just regrowing what was already there?
Anything you cut off a plant, is wasted energy, wasted nutes, and wasted time. There had better be a damn good reason before you take the scissors out.