The component minecraft:can_climb is supposed to allow mobs to climb ladders. However, mobs only use seem to use this randomly and very rarely, or when pushed continuously into a ladder. They never use it to reach determinate pathfinding goals such as fleeing from another mob, moving to reach a POI, or tracking a target.

Steps to reproduce

1. Use Climb fail-1.mcworld. It contains boxes and elevated walkways with ladders. Command blocks can be used to spawn a certain mob in each box, to switch day and night (on the elevated walkway), and to send everything to the void for a quick reset (the floating command block).
2. Spawn mobs in each box using the command blocks and watch for a while.
3. Spawn a cat in the creeper box with a creeper.
4. Use the command block to send all to the void.
5. On the elevated walkway with the bed and workstation, spawn a villager on either end, then toggle day/night so that it tries to path to either the bed or workstation.
6. On one of the elevated walkways that does not have a bed and workstation, spawn a husk on the lower part and a villager on the upper part.
7. On the other elevated walkway that does not have a bed and workstation, spawn a llama on the lower part and a wolf on the lower part closer to the ladder.

Expected results

• Step (2): all of the mobs eventually wander out of their boxes using the ladders.
• Step (3): the creeper uses the ladders to escape from the cat.
• Step (5): the villager uses the ladder to reach its bed or workstation.
• Step (6): the husk uses the ladder to reach the villager.
• Step (7): the wolf uses the ladder to try to escape the llama.

Observed results

• Step (2): the slime gets out quickly, the animals occasionally go up the ladders and may eventually get out but usually fall right back down after going up, and the zombie and creeper never get out.
• Step (3): the creeper mostly does not escape the cat; very rarely it may go up a ladder (probably because the cat pushes it) and even then it is likely to fall back down again.
• Step (5): the villager stops at the ladder and does not use it.
• Step (6): the husk stops at the ladder and does not use it.
• Step (7): the wolf stops at the ladder and does not use it.