I've played a lot more of the game since my initial impressions now and...it's still boring. Sure I'm doing a lot more sidequests now, but the sidequests themselves are all of the most tedious and uninspired variety imaginable. Go to point and kill something. Go to point and collect something. Bring something from point 1 to point 2. That's pretty much it, over and over and over. Come on, people complained about shit quests like these back in the 90s. That's not even an exaggeration. The fact that a huge flagship product in a long-running franchise thinks this crap is acceptable in 2016 is just sad.
Thus far the only sidequest I've done that I would describe as even remotely interesting is the deadeye hunt. Which in the end was still just a kill X quest but at least it had some actual build-up before that, having to track deadeye back to his lair and shit.
Speaking of hunting quests, it's kind of sad that Square Enix did hunting quests 10 times better themselves 10 years ago in FFXII. In FFXII you had to gather information on what you were hunting, track it down, and for the later ones at least special tactics were often necessary to kill them. Plus there was a whole side-story that unfolded as you did the hunting quests. In FFXV though...it's literally just follow marker to point and kill shit. That's it. Rinse, wash, and repeat. Admittedly the early FFXII hunting quests weren't super-interesting either, but given the way they structured them in FFXV I can't really see them ever improving. At least outside of the rare exception like deadeye, which was ultimately tied into another non-hunting quest anyway.
A perfect example of how little thought they put into their quests would be the dog tag quests. The way it's initially described you would think it would be an ongoing thing where if you happen across dog tags bring them back to Dave. Instead they're given out exactly like every other quests and Dave apparently has some sort of magical knowledge of exactly where every single dog tag is so you can just follow a marker straight to the tag. And they're usually not even very far from where Dave is standing at that moment. Damn it Dave, just go pick them up yourself. How lazy are the people in this world?
The problem isn't just that FFXV is an open world game, it's that it's a really bad open-world game.
Sounds like FFXIII-2 then. It was all useless fetch quests that involved blah, wanting blah, from blah, who was generally in the same vicinity of blah, but at blah time.
The problem with sidequests is that generally the rewards aren't worth the time to even bother with, which makes the already tedious 'fetch/kill x' quests feel even more insipid. FFXIII-3 at least had the decency to tie stat-ups to sidequests rather than just a piece of vendor trash or two and maybe some cash. Xenoblade Wii made the mistake of making sidequests give out Exp and Money, neither of which were actually useful to the player (as Exp increases levels which diminished AP and SP gains from enemies, you might as well farm Exp from enemies and discoveries instead, and the only items you ever really needed to buy with your virtually infinite funds were those Arts Manuals), but at least it also provided Affinity bonuses and a Gem or two that didn't actually suck.
If I'd have to describe a good sidequest, it'd be one where you got involved with the lore of the setting a bit (like exploring some ancient ruin from a 1000 year old war or something), gave you an actual dungeon that you'd otherwise wouldn't see by sticking to the story (maybe a lava cave with a gimmick that you would only see briefly during the main game), lined said dungeon with chests filled with items, equipment, spells, etc; some of which you wouldn't see anywhere else in the game (like a shield that might teach an endgame tier spell or something on top of a high-end sword and some nice female only armor along with the usual Elixirs and such), and topped off with the occasional boss fight (perhaps some kind of loot hoarding dragon or something).