I was a huge fan of Breath of the Wild when it came out and played the hell out of it. At a certain point, it felt like I hit the logical end point and there wasn't much else to do. When I started playing Tears of the Kingdom, I got exactly what I wanted which was more Breath of the Wild. I'm still playing ToTK and really enjoying it.
Tears of the Kingdom is more of a lot of things. The expansive world of BoTW was expanded even further upward to the sky and downward to the depths, the combat is better, the annoying mechanics are remedied, there is far more to experience, there are many more missions and things to collect, and there is far more customization and sophisticated use of the systems invented by Breath of the Wild. As I've been playing it (many more hours now than I played BoTW), I've been thinking about why I don't love it like I loved BoTW despite it me having more fun with it.
It's not uncommon to be disappointed by ToTK, and I've listened to many negative reviews. Oddly, I agree with most of what they say short of believing the game is bad or really failed in any way. I think ToTK is doing a different thing than BoTW. While ToTK fixed many mechanical issues from BoTW and added so much that BoTW might as well be obsolete from a gameplay perspective, ToTK completely lost the vibe that BoTW had which was that game's primary strength.
Breath of the Wild is mysterious, melancholy, and beautiful. It's a game about exploration in every way. Through the experience Link learns where he is, who he is, and the context of what is happening in real time with the player. The world feels especially dangerous because you start with literally nothing and you don't really know what's going on. The intrinsic and extrinsic rewards to the game are all to do with exploration. Seeing a century-old battlefield littered with the weapons of fallen soldiers amidst the ruins of a village totally reclaimed by nature is a particular kind of emotional experience, and there are many such experiences throughout the game. Unfortunately, there is only so much to discover and once the map is filled out, the cutscenes are seen, and Ganon is defeated, there isn't much to do after that but poke around the world for its own sake or test your patience with the annoyingly difficult DLC.
Tears of the Kingdom, a continuation of the story, is not so much focused on exploration. In ToTK, exploration is one of the many fun activities the player can do. The overworld is the same with some minor differences such as a network of caves, and the skyworld and underworld are filled with treasure and beauty but not much in the way of themes or emotional resonance. Far more so than in BoTW, the world of ToTK feels like the player's personal playground to experiment with and relax in. It's just not that serious.
Unlike in BoTW, it's easy to forget the main antagonist is even a problem in ToTK. The game is more interested in world building for its own sake. For example, the people of Kakariko village are far more concerned with local archaeology than the potential doom of the world. Most characters in the game are more concerned with their low-stakes slices of life than Ganondorf politely sitting in the castle and not threatening them at all. No one is in any real danger. Groups of villagers attack monster camps with ladles and pot lids and not one bad thing can ever happen to them. The tone from the previous game is obliterated, but it's fun, and I don't think this is a bad thing. I am ok with the focus shifting from discovering the world to greatly expand the capability to goof around in that same world.
I would say that BoTW is the meal and ToTK is the dessert. Many people were disappointed that ToTK wasn't another meal of the same quality as BoTW, but personally I'm ok with having dessert.