[Spoiler?] Is teleportation just a player convenience and not a real thing?

[Conradus]

Oh no how will we escape Ul'dah? Teleport?

No we need to plot-twist sacrifice people. Which is fine....I just would have preferred if there was an explanation, probably involving magic, as to why people didn't just poof away with teleportation.

I'm just having difficulty with the concept that people don't actually teleport with the prevalence of Aetheryte in every major outpost and an Aethernet in every major city.

And why didn't they just use a Phoenix Down on Aerith?