A couple of my favourites :

• Days Gone
• Metro Exodus (I would recommend you play the 2 previous games before to understand the story. They are linear, so if you do not like that, simply watch a playthrough of both of them. BUT. I highly recommend you play and experience the atmosphere of the first 2 games, just my opinion)
• Older Assassin's creeds (BF, Unity, Creed, Brotherhood, etc)
• Witcher 3
• FFXV
• No Man's Sky
• Need for Speed Unbound/Heat (which ever one is cheaper, I prefer unbound, but they are pretty similar.)

And, if you have a good computer that can emulate switch games, I would highly recommend BOTW and TOTK as you've mentioned in the post. The best open world games there are.

For Spider-Man, I guess the easy answer would be Miles Morales, huh? :P

But I know what you meant, its a game with ridiculously fun mobility though its hard to find a good equivalent. There's few things that feel as good as webslinging. So on that front (Open world + Mobility) I'm going to suggest the Just Cause series. 2 is generally the one people are the most fond of, though I vastly preferred 3. 4 is a mix of both but it didn't gel well with me. You are not quite Spider-man, but a grappling hook and wingsuit go a long way of providing a similar experience.

For Genshin, the one game with open-world and exploration I've swapped around with it before is Assassin's Creed Odyssey. Large world, fair number of sidequests (I've actually never finished the game from how big it is) and a lot of climbing - with no stamina bars. The loot quality feeds the same endorphins as a good gacha roll, and its free.

Morrowind! Besides the wealth of non-story quests, the modding community is HUGE and lets you add EVEN MORE CONTENT. (To be fair, the modding communities for all TES games are massive.)

What's better than going to the main inspiration of Spider games? Insomniac already said that a huge inspiration of their games is the Batman Arkham Series. They play very similarly but with Arkham being more focused on stealth and puzzles. The first one, Arkham Asylum is more of a metroidvania than an open world, so I think you could start with Arkham City (the second one). As for Zelda, you could try one of its copycats, Genshin is one of them, the other one would be Fenyx Rising, a Ubisoft game. I have never played, but from what Ive read, it's pretty good.

I found Saints Row 4 a fun super hero video game and the powers of super speed and flight made traveling fun over conventional means. The side quests were something I enjoyed too.

I second No Man's Sky.
Maybe Subnautica. I love just swimming around with my stereo system blasting all the alien ocean creature sounds.

No Man Sky definitely has that open world sandbox itch. There's a lot of stuff to do it. Also go and pirate tears of the kingdom lol, it's super fuckin good.

How much do you care about the actual combat?

There are an absolute ton of games on Steam that cover the exploring and doing quests vibe and the amount of combat in them varies from none to some but not the main focus of the game. Here's a few I've tried:

• https://store.steampowered.com/app/1307550/Craftopia/
• https://store.steampowered.com/app/1401590/Disney_Dreamlight_Valley/
• https://store.steampowered.com/app/361420/ASTRONEER/
• https://store.steampowered.com/app/275850/No_Mans_Sky/
• https://store.steampowered.com/app/648800/Raft/

Also practically anything in the survival and MMORPG genres are full of just chilling in the world content too.

Perhaps not quite as quest driven, but if you like open world combat, check out the Shadow of Mordor/Shadow of War games. Don't take the story too seriously, but they are a fantastic good time.

Enemies that see how to approach them, and if you are too same-y they'll adapt. Focus too much on stealth kills? Enemies have stealth pierceing guards. Tend to go direct melee combat? Big bruiser show up that force you to respect them and dodge. They are not perfect games, and they're a bit older these days, but nothing beats the hunter turn hunted experience of that first play through. I've beaten it years ago, but once in a while I just let my castle fall and go on an orc hunting spree to mastermind a take over once again.