I think the real issue with locking flying behind grinds/renown/other walls isn’t really that we have to do something to earn it, it’s that flying itself is busted and requires these heavy-handed solutions not to completely trivialise large portions of the game. In other words; the issue is level design.
Flying is not just a convenience, it allows you to effectively skip large portions of the game in order to get straight to the end goal. As is pointed out here:
… world pvp just doesn’t work when flying exists, because you can just fly high enough that no players can reach you. The same can be said for many enemies in the game, they’ve been put there for a reason, and if you can just fly past all of them and ignore them, they suddenly feel much more pointless. No wonder the devs don’t want to give you flying to start off with, they want you to experience the game as they have designed it, and flying breaks that because it is so powerful.
… but I do think they’ve gone about it the wrong way. The issue is level design, and much of the level design doesn’t factor in flying. If you can fly away to safety so easily, why put threats that can be countered that way in, in the first place? The only way you can now justify that those threats exist, is to say, “you can’t fly here yet!”… if the levels were designed with flying in mind from the get-go, we wouldn’t need to gate it behind a grind.
If you ask me, though, I also think flying is too powerful. You can quite literally get out of reach of enemies within seconds with a flying mount, and NPCs are leashed almost as soon as you take off from the ground. Once you’re in the air, you’re practically invincible and you can even AFK. I understand why no one wants to change this system as it exists now, though, because people might find it jarring to have this insanely convenient system made more complicated. Just some random ideas I’ve just had: add a wind-up time before you can start flying, make flying an active process where you have to press space to flap your mount’s wings (or equivalent), add threats that exist in the air that forces you to react to them.
Ultimately, I think gating flying behind the big Zereth Mortis cypher system is okay, I just think it’s a bad solution to a wider problem. And if it is going to be gated behind a system: don’t gate it behind a grind, because that will make players want to rush to the finish line and cause them to burn themselves out, and don’t gate it behind an arbitrarily long timegate that will only cause frustration. My suggestion (beyond fixing flying/level design) is gating it behind doing all the quests, and then 50% of the rares and 50% of the treasures, or something along those lines.