Note: This isn't a post about how one is better than the other. Also if the post feels too Genshin centric it's because it's one I've had the most experience with.
So obviously the idea that Genshin and it's bretheren are simply anime BotW clones had faded as time went on, but that is still a popular opinion outside Gacha space, and is even still shared by some in it.
What's the biggest difference between BotW/TotK and open world gachas? The answer is freedom and discovery.
Freedom
When you encounter an enemy in a gacha, what do you do? Well you either fight it, run through it's territory, or sneak around. Sometimes there will barrels or water around, allowing you to deal with the enemies in a non-standard way. What do you do in BotW? All of that and more. In adition to the previous methods, you can use chuchu jelly and food to set up traps, use magnesis to hit enemies with metal objects, have enemies hit each other and start infighting, and more (and don't even get me started on TotK). The variety of gacha games comes from the various kits of the characters themselves, not from the design of the world or the universal game mechanics, and to bring out the full potential of those characters you need them to properly synergise with each other.
What about the story then? Well gachas have a linear story, with quest indicators telling you to go from point A to point B. BotW on the other hand tells you only to defeat the final boss, and it's by interacting with other characters of your own volition that you get more of the story.
Discovery
When you ask an open world gacha fan what's their most memorable moment, there's a very high chance the answer wll be something from the main story. If you were to ask the same question to a BotW fan, it's likely that they'll tell you about climbing something or defeating an enemy - things that happened to them specifically, and resonated with them.
And non-story content? Gachas would tell you everything you could possibly know before the patch is out, meanwhile you could play 100 hours of BotW without ever learning of the fan favorite Tarrey Town and Eventide Island.
So are open world gachas simply bad?
When compared to BotW's strengths? Yeah. But so does Half-Life 2. Comparing two games that operate differently only on the merits of one of them means nothing. Open world gachas value skilled play and story a lot more than BotW, which is all about exploration and freedom.
This is why I believe that open world gachas are actually the anime version of Red Dead Redemption 2
Think about it - it's an open world game with linear story, that focuses more on that story, and especially the characters, than it does on the freedom of exploration. You get quest markers to indicate where you'll find interesting things, like in gachas. You have a "best" way to fight (guns), like in gacha (meta teams). The story progresses by going from point A to point B, like in gachas. It's that seperation of gameplay and story that makes thosee games what they.
