I don't hate them (zone level designs), just surprised at some of the simplicity or lack of exploration / 'gameplay' wonderment. I say wonderment because sometimes it's a puzzle or some backtrack that makes you go "ah-ha!". I always considered the environment as a non-verbal character of the game, so interacting with it should be a deep conversation- Souls like games have good practice at silent conversations (including environment). I just felt the gameplay elements of the zones in FFXVI didn't really 'silently' talk to me. Visually, including the visual design not just 'graphic quality' of the landscapes talk very well though- I am often pleased with the visual layouts.
Personally I think what bothers me about the open world, and is also just probably a pet-peeve in general which makes it further personal lol, is that there are so many invisible walls. I see a small rock and think I'll hop up on it and the game is like NAH, YOU GO LEFT, OR YOU GO RIGHT, AND IT GOES TO THE SAME SPOT. Me: "how about this cliff". Game: "YOU GO LEFT OR YOU GO RIGHT- YOU GO TO SAME PLACE I TELL YOU, YOU TWIT". Also probably with a preconceived notion on top of that which was they would improve FFXV's open world exploration which did have some stronger movement controls- so I was pre-hoping for smoother environment interactions. The blending from running to hoping over fences is nice, but the jump is uh.. not very useful and you can imagine most of the game as a 2d isometric (in terms of movement, not visuals obviously). Something about being stuck on the ground, essentially, in a 3d world space, really gets to my monkey brain- 404s and dial up noises right away lol.
So I had visual exploration, but I felt I didn't have much tactical exploration. I think this is made a bit worse by the fact that, and you pointed this out I believe, the general rewards for exploring is like 2 gil and some wyrite lol. Doesn't really feel worth it and doesn't really feel like exploring anyways. I do appreciate that chests get their pop-up icon though, otherwise chests would be invisible lol. Next time I hope they can try to add some more interesting rewards, recipes, music rolls, etc. Probably similar to my feeling on quests, most are fairly straight forward (mechanically- tasks/rewards), but when I did the herbal quest that rewards you better potions I was like "now that's cool, worth".
Just finished up a few more hours of play after some MSQ and was like damn, have to wait to do more (till next available time to play).. So that's a pretty good

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Funny I said I didn't intend to comment much, but it was nice enough to talk to you that I couldn't help have small thoughts while playing XD.