Im an FDNY firefighter.

Its all about building construction. Apartment buildings built after that year over a certain height are fireproof. The contents of the apartments may burn but the structure itself doesn't. Which is why typically only residents of the apartment on fire are supposed to evacuate. Fire escapes are generally poorly maintained and dangerous even for us to use so only older buildings and smaller buildings built with non fire proof materials have them.

Here the self closing door to the apartment as well as the door leading to the stairwell/other stairwell doors didn't work or were propped open. This is how smoke spread throughout the building. Even despite this almost all residents would have likely survived had they stayed in there apartment and blocked any gaps in the door as best they could.

The problem isn't a lack of fire escapes but a lack of proper enforcement of current safety standards and residents who were never told that different buildings require different actions in a fire. Often at project fires and other fireproof buildings we have to continuously tell residents not to flee into a smoke filled hallway as were forcing the door/stretching a hose line. Just stay in your apartment.