Correct, there is no need. It is more of a preference, maybe a challenge or code golf type of thing. One advantage is less thinking / decision / boilerplate is needed when adding elements.

Semantic:

p

Normal:

p class=paragraph

Utility:

p class=mx-1 py-1 my-2 text-medium

It is like buying a medium shirt rather than getting a tailor-made t-shirt.