Some special spellcasters are very safe when riding magical beasts through the sky. If they fall, they just need to quickly protect themselves with a spell.
However, the problem is that there are hardly any of these flying mounts. Only legendary Animal Mages can breed them, trying to induce mutations in existing large birds to turn them into magical beasts, improving their carrying capacity and temperament before they can be used as flying mounts.
This process takes time. Even for mutated griffins and golden eagles, it's challenging to carry a person for long-distance flights, so efforts have to be made to increase their size and flying strength, and ideally, they should gain some extraordinary powers.
Therefore, it takes a comparatively long time.
Currently, there are a total of only five legendary Animal Mages on the whole Blue Star and Emu combined. They are all interested in flying mounts and are trying their hand at breeding and domestication.