I would disagree with this sentiment on a basic game design level. I don't know about the Zelda games, I didn't care enough about BotW to play more than a few hours, but designing a large map that incorporates multiple biomes in a believable way is much more difficult than creating a bunch of smaller levels that don't have to have any relation to each other in the slightest. You can get away with a lot more in terms of map geometry and set pieces when you load into each level individually.

This is obviously different when you're talking about Bethesda-style load into every building style environments vs Elden Ring "You see that castle in the distance? You'll be going in there eventually" design, but the fact that Bethesda makes their interiors separate from the rest of the world is how they cheap out on their games. It's less hardware intensive and you can cheat a lot more in your design. And on a gameplay level that goes for Ubisoft-style collectathon map objects (and Zelda shrines in this case), but that's not unique to open-world games - it's a lazy cop-out that game devs have used forever to pad out their games. Collecting all the secret skulls in Halo is the same thing, but because it's implemented well and doesn't drag on forever with no reward like most open-world collectibles, it feels totally different.