Not if it's done well. A bit of lore and interesting quests can save this very easily. Also, why would airships be pointless in such a massive world? Even with a large world it's not like you can't block off certain areas via lakes, oceans, mountains etc.
Fun fact: You actually can't climb mountains in a lot of open world games. Crazy I know.

A lot of rpgs have optional towns and dungeons, hell, even FFXII had them and they were great.
Obviously fast travel is more convenient than an Airship section with 2 or 3 loading screens for worldmap and regional map, I don't really care if open world is done well or not, I am not interested in open worlds or sidequests.