How does a porch look on an apartment (building), then?
My apartment and several in the area, have a concierge, and they’ll act as a “porch” and even deliver it to your door later in the day
Some apartments have mail rooms, some with automated entry based on if you have a package or not
It’s largely a solved problem
dairy man
mailman
seltzer water man
whomever else delivered stuff man
but, they also probably had someone at home all day.
I also think having a general unlocked mail or package slot is problematic these days, as bad actors could use that to insert all kinds of nefarious and damaging items into your home.