You're not a real photographer unless you shoot people.

Portraiture is the purest and most artistic form of photography bar none. Through portraiture you develop and exhibit the bare minimum of skill needed to engage artistically with other genres and employ some directorial talent to truly create the images you want, not just the ones you stumble into. If you never engage in portraiture you will never, ever develop anything resembling talent. The portrait is the fundamental skill, the pure photography. It is the deceptively simple dish that must be made perfectly, the one that amateurs fail at despite being decent at more complex meals, that you must master if you are ever to truly master anything else.

This fact is not up for debate. Even Ansel Adams did decent portraiture.
https://www.artsy.net/artwork/ansel-adams-portrait-of-brassai-yosemite-california