They’ll stop a stranger walking out with a package and keep an eye out for your abusive ex for you. They won’t remember you coming home late 6 years ago shortly after someone matching your description left an abortion clinic.
They’re also human not an unaccountable automated process. They’ll let you bring home a new fling 5 nights in the same month without registering them as a tenant, and let a non-corporate delivery driver drop off a package without being registered as a SurveillanceCorp approved deliverer.
The concept of doormen is dumb, but we don’t need to automate away every human interaction in our lives.