When a blaze pathfinds randomly, it will never pathfind where other mobs would take fall damage, despite being a flying mob. To reproduce, place a blaze on a 4 block tall pillar and notice it never goes off the pillar.
MC-183706
Blazes try to avoid fall damage, despite being flying mobs
Open
16
(Unassigned)
Confirmed
Mob behaviour
1.15.2, 20w19a, 20w22a, 1.16 Pre-release 1, 1.16 Pre-release 2, ..., 1.20.4, 1.21, 1.21.1, 1.21.3, 1.21.4
Retrieved
This is very important, because as flying mobs they should fly over those places to be safe.