I think TotK improved on a lot of things of BotW. It was obvious BotW was kind of a "testing ground" for an open world Zelda. To me TotK is just BotW 2.0, there's a lot to like, but because it's so similar it carried over a lot of the downsides of BotW as well IMO.

It's vastly improved, but I still think there's a lot of room to improve even more. Here's hoping we get a third game in the "series" and they can keep the momentum going

Some things I thought that improved:

The powers. I think the powers in TotK feel way mroe fun than the powers in BotW, and mix a lot better with puzzle solving.
The building. Adding a Garry's Mod-esque building system is perfect for a "make your own fun/solutions" kind of game that an open world incentivizes
Temples. It's nice to finally have temples. They could still use a bit of improvement as they're rather straightforward and don't require any crazy interesting puzzle solutions, but it's better than nothing.
Shrines. The shrines in BotW were fun but I feel like the shrines in TotK had more thought put into creative puzzles and puzzle solutions since there was a lot more we could work with (powered flight, reversing time, being able to move through things. Manipulating items to fit into things. Fusing)
I think they did open world pretty decently, but overall I still think having a large open, but linear set of areas makes for a better paced game.

Some things I thought still needed improving:

I know this is a supier lukewarm take, but I still think these games would be vastly imrpvoed without a durability system
The story, while present, left a lot to be desired. I know they're not ultimately the main draw of the game, but I still wish they put a bit more effort into it and didn't have so much of it be so on the nose.
The depths. They're a great addition and add to the minute to minute gameplay, but really it just kinda felt like a place to go just to farm specific materials or gather poe. I wish it had more a larger impact on the story or lore.

Some random things:

I LOVE the music
Playing this game on Yuzu at 60FPS and 1440p is very very nice.
There's some clever puzzles and interesting things you can do to the point that I wish they included some kind of sandbox mode where you can just build and test machines to your hearts content