The hair under the armpit can be removed with a hair remover, and will not become thicker and thicker.
After depilation with depilator, the newly grown ones will not become thicker in the future. It’s completely false to feel that the hair shaved too long is thicker, because the process of shaving retains the root of the hair, which is thicker than the distal end, so the newly grown hair will be thicker than the hair with the tip, look black, and appear dense.
Whether the hair is more or less, thick or thin, black or light, has nothing to do with cutting it or shaving it, but is determined by genes and hormones.
Human hair grows from hair follicles. Hair follicles that directly affect hair growth are hidden deep in the skin. The hair inside the hair follicle keeps growing, and the hair outside the scalp is dead. Just cutting and shaving the surface will not affect the hair follicle, so it will not affect the state of the hair.