honestly I think my favourite thing about BOTW is that

you see that mountain? you can go there. go climb it.
You see that island just off the coast? You can go there too. Get a raft, sail out.
You see the top of that talking tree? haha climb that fucker he don't care.
see that fortess? go kick ass.

and more often than not, doing these things is rewarded with:
a korok
a special trial with a shrine at the end of it
a shrine on its own with a mini trial inside of it
some sweet loot
a questline.