You need stairs and walkway early on

[PrometheanAscent]

You get conveyor lifts earlier, than you have access to stairs and walkways. Whichs means, before you have an Awesome Sink and an Awesome Shop to buy stairs and walkways, you only can use space intensive foundations and ramps to get on higher floors. And you cannot build stairs with them, which often results in jumping over edges.

I for myself use a Lookout Tower as stairs, but this is very unpleasing.

I think, such necessary elements like stairs and walkways should not just unlocked with two additional buildings, but should be available, when you get foundations, walls and conveyor lifts, so you can build more than one floor and actually reach it efficient.

And if you have walls, you also should have rudimentary gates and openings for conveyors in walls at the same time.

[Mr.America]

I can see the argument for stairs, or at least, ladders early on. Having replayed the game from the ground up, vertical movement is a pain to do early on, even though you can build vertical almost immediatly, making early factories look VERY unpleasing to the eye after progressing further as you can see the unnatural design not made for manual traversal.

The gates are not that much of a problem, you should usually just leave the wall empty if you intend to pierce it with a belt and only later add the special walls. It is easy to fix and doesn't look too bad when just left empty.

The problem with no stairs/ladders is it affects the design of the entire factory if you don't have them. As such I'd add ladders from the moment you unlock automated iron rods.

[Casurin]

It makes no sense from a gameplay perspective, story or aestetic.
You are literally building an elevator to outer space, giant concrete/steel ramps, but you can not build a simple stair or door?
There are many simple conveniece options missing early-game.
I would also say that before building hypertubes you should be able to build simple elevators (for vehicles and personal use)... after all you already have the technology for them with the conveyor elevators and a vacuum-tube-system is far more hightech there.

[Man's Best Friend]

The thing is, while I don't disagree that it might be nice to have stairs earlier, the fact is that verticality isn't particularly important at the point in the game where you can't get them.

[Air Bear]

I think from a developer perspective, its probably an incentive to get the player to engage with the Sink and Awesome Shop.