Answer:
Stairs, escalators, elevators, ramps...
Step-by-step explanation:
If ladders are difficult to use for high floors another very common options are stairs. you see them pretty much everywhere. Escalators and elevators are also used, elevators more often that escalators.
I don't know how to make it sound "mathy" but..
Ladders are super straight and so for high floors, the slope of the ladder will be too steep for anyone to climb without gravity interfering.
The level of safety with stairs is higher because instead of going straight up, The steps provide a flat surface for someone to stand on while climbing the stairs and there is a much more stable foundation. Stairs can have protection like a guard rail and even go in a spiral motion upwards because they are more stable and safe. It is still possible to fall if one is not careful because of pesky gravity.
Escalators are pretty much moving stairs and the level of safety is greater because of the strong foundation and flat surface to stand on. Of course falling can happen, lowering the safety, but this is not likely because of the slowly enough moving steps. There is a rail as well and as long as people are careful, there aren't usually any casualties.
Elevators take up way less space than stairs and escalators because they can go straight up and down. The level of safety is fairly high because an elevator is a pulley system and people don't involve all that much moving around. Just go in the mechanical box, the doors close for safety, click a button, and then go up or down.
I don't know how to incorporate mathematical facts into this question because this is literally logic not math in my opinion. Honestly, ladders aren't even used that much, I don't think, except for building and house work.
I hope this helps you with whatever you are doing!
<3
