Something I'd like to see in 5.0 (or sooner...) would be an upgrade to the inter-city Aethernet. This, like flying mounts, would be something you'd have to work towards.

The basic premise is that you can now teleport to a specific Aethernet point (Let's say Hawkers' Alley in Limsa Lominsa) by either clicking the point on the map or right clicking Limsa Lominsa Lower Decks from the Teleport menu to bring up the individual Aethernet points).

The advantage being you no longer have to go to an Aethernet Shard to teleport within the city, you can just do it at any time. But not from outside of the city, so you couldn't teleport from somewhere in the black shroud directly to Hawkers' Alley.

This could be unlocked/implemented in a few ways
1) Either one large quest to unlock this per city.
2) One massive quest that unlocks it for all cities.
3) Just give it to everyone a QoL update.
4) A little crazy and I'll regret posting it if this was chosen, but you could implement a drop system where any mobs within the cities "zone" would have a chance at dropping a crystal when you kill them (within say 5 level difference of your won levels). You would then need to travel to each Aethernet Shard and apply that crystal to it, so you could unlock a few at a time and start with the ones you like the most, etc. Would encourage a little more open world content which has been pretty dry for a while now.