Yeah okay, I think I might go buy it in 2-3 hours. Really hope there's stuff I can explore and cool things to get. Secret things like armor and gear and equipment. Or maybe all of it is only through shops and stuff like that?
Something the game fails at is validating exploration with tangible reward. There are lots of collectibles and whatnot but for the most part it doesn't lead into anything significant. You can't find armour, weapons and whatnot, you can find bits of information that get added to your encylopedia.
Early on in the game I swam off to an lone island thinking there might be something of value there. Nothing at all.
With that said, exploring is still intrinsically rewarding because of how beautiful and varied the game is. The situations you can get yourself into with combat, hunting down bots for resources (some of these can provide rare loot which you can augment to your existing equipment, which does provide a good sense of reward).
I don't want to put you off it though, it's the best open world game / action-RPG that I have ever played. I'd recommend it to anyone, but that doesn't mean that there isn't room for improvement either.
I played a tiny bit more. The side quests and "errands" seem to fall into the same traps as other RPGs. Basically the first one has you kill five rabbits, which is exactly the kind of thing Witcher 3 tried to avoid.
As far back as Witcher 2 CDProjekt tried to find ways around that kind of quest design, usually by making the process deeper (destroy three nests) or adding some quirk to every one of them (solve a puzzle at each one, or make some kind of moral choice). More importantly Witcher 2 and 3 tried to make the tasks in their quests seem less mundane. I point this out because Horizon draws a lot from Witcher 3 and that's exactly what makes Witcher 3 stand out among open-world RPGs.
Haven't gotten my copy of Zelda yet but I hear it's a lot more systemic than most of the biggest open-world games around today. People are comparing it to Far Cry 2 in that aspect. What I'm starting to think happened is Nintendo fused the open-world formula together with some Minecraft-esque survival elements and the latter's totally open structure, and may have even borrowed more of Skyrim's systemic systems than any other game that pulls from Skyrim. Most games that do so seem to only borrow Skyrim's interface and overall quest structure, but not the way NPCs and the world react to the player and each other.
Anyway, before I digress too much, if I get more interested in Horizon for any reason it'll probably be the setting and story. The actual game is a smorgasbord of other games but the setting does post-apocalyptic in a way that's a bit different for video games. I'd like to get into that first town and see the other communities.
I didn't encounter one asking me to 'kill 5 rabits'. Every side quest and errand I have completed has been tied significantly to a narrative. I'd suggest playing more of the game before attempting to provide a significant critique of the games quest structure. I don't think it's perfect but it's not the 'do x number of x things' that you describe here. If anything the side quests are too much like The Witcher 3's, the only problem I have had with it is the NPCs don't express that much personality. I didn't find myself connecting with the short stories that they offer in the same way as I did with W3, and in most cases they only have one quest for you, whereas W3 has much longer sequences.