If you think about it ladders, along with the wheel, figure throughout history.
From sieges over the centuries, to construction, and for access for countless purposes, to shipping (the rigging and so on) - the ladder is always there somewhere in the past whether near or distant.
On top of that, a ladder is only used when it's needed to be used. Hence my thing below about Neil Armstrong. He used a ladder to get down onto the moon.
How Freud related it to matters sexual is a mystery but there again a lot of his theories have long been thrown in histories dustbin as meaningless.
Jung (his student who suppased him by miles) reckoned things related to territory and ownership.
Anyway, what dreams mean can never be proved but one thing is for sure, I don't dream of ladders, I have nightmares about them as in 'falling off'.
Roll on WFP for us.