Idea:

High payload delivery quests.

Reward: full 2,000 White Scrips

Process:

You get an extra delivery NPC that sends you to some town that needs a delivery to the other side of the world. The package is too big to teleport or fly with.

Upon accepting the quest
-All Teleportation is disabled
-All Flying is disabled
-Only your chocobo is useable, for extra flavor he can be towing a little cart (a more liberal version on this would include all mounts) (I feel like this could be an activity you could share with your chocobo, you know the iconic FF mount you forgot you had?)
-You have to travel by land, to your destination, as a reward you fill all your scrips weekly.

Achievements:
-There would be reason to farm map to increase chocobo speed
-There would be a reason to use your chocobo and get a nice barding for it other than cannon fodder in fates
-Populates the overworld on a weekly basis making it look more lively
-Introduces a different type of content that is optional

I think I'd look forward to this quest more than the roulettes or anything else to be honest since I'm bored of instanced content.

Extra:
In a funner version of this, you could have an RNG chance of encountering random enemies along the way that bind your chocobo and you must defeat them to keep going. An open world encounter where other people can help, or just ignore you. Something casual, not hard. It would be reminiscent of old RPGs where open world travel could result in a battle encounter. (since this combat idk if people would like this for delivery quests but the idea is there)

Either way I know I would enjoy travel in this game that's not port to A, port to B, done. And flying also desensitizes you to some extent and might be too convenient for this, plus if you're carrying something heavy there would be a reason not to overload your mounts.

I feel like others would look forward to travel based content.