The world feels almost real, every hill, wall or tree is climbable, every crevice has something interesting, if you just swing your sword in a field you'll cut grass and lizards will pop out. It's hard to try to go on a mission and not get lost going after something cool that you find along the way.
It’s not really like other Zelda games, nor really an RPG. It gives you lots of freedom and bodily autonomy, but personally I found it very hard to piece together an interesting experience out of the (admittedly very flexible) constituent parts. It’s an extremely good physical simulation of a world I struggled to care one iota about, and there were so few ways to express yourself as a character that you can’t really tell your own story in your head. I sometimes feel similarly about the Assassin’s Creed games - what a lovely engine, that gives you this unique feeling of freedom even within a huge, teeming city, but I wish somebody would make a different game with it. I don’t think you’d enjoy it coming from western RPGs, with slightly meatier worlds and a more developed sense of self. It’s more like Minecraft, if anything.
Zelda games are generally considered in the action-adventure genre, rather than RPGs (though this is controversial). Unlike the RPGs you mentioned, there are no explicit stats that you can choose to level up. There is no min-maxing of numbers. Progression is your own gameplay skill improvement and items collected that assist either giving abilities you didn't have before, or are stronger than previous items.
I think Zelda games are in a league of their own, and always have been at every generation. The general mechanic is being able to initially explore, yet running into obstacles that prevent you from going many places. Then you solve the necessary puzzles and kill monsters to acquire tools. Finally, you must figure out where when and how to use those tools to overcome those obstacles to travel to previously unreachable areas. Its a very gratifying experience the first time through, and there is a lot of replay value in the games too.
Haven't played TOTK but its predecessor BOTW is one of the best and most open immersive open world games of all time. All physics mechanisms work with other mechanisms and if you can see something, you can go there/interact with it. The map is also big enough thats its in top 10 largest open world maps and from what I've heard TOTK has more than doubled that in size.
The reviews claim that TOTK has only improved in the immersiveness aspect as well.
The fact that it runs on the switch (and they managed to fit it in 18 GB) is a huge feat.
The thing I liked about it was how beautiful the puzzles are, really simple but fun to solve and figure out, often teaching you a new skill as you go. Fighting is also quite fun.
The thing I didn’t like was its easy to get off track and laborious to get places super quickly.
Also I didn’t really get the food/items/combinations system at all, it’s quite unexplained as far as I could tell.
I can't really draw a parallel to those games, probably the closest would be to fallout, the open world 3d ones specifically. BotW & now TOTK have a massive focus on it's world and it's pretty immersive to clamber over mountains and discover things. It has unique systems to interact and traverse the world, improved further in TOTK.
If you've played any open world game, it's pretty much the same, just a little more formulaic. Characters, story, world are all incredibly basic and predictable. You'll stop finding truly new things after a few hours, making exploration more of a chore than anything else.