I think a lot of this commentary is being remarkably uncharitable when it comes to the depth of the fiction experienced in Story Now play. It basically paints Story Now GMs as remarkably lazy and undisciplined. We're not space aliens. We're just directing our energy to a different place. Assuming an equal amount of effort there is going to be more depth / detail where you spend your energy.
In any game some elements of the setting are going to more tangible based on where effort gets expended. Some will be less so. That's why it is so important to be mindful of where we spend our energy. Platonic sandbox play tends to feel more tangible to me when looking at things that are further away from the PCs' present situation because the GM is spending a lot more time and mental energy on those things. Platonic Story Now play tends to have a lot more detail and depth devoted to things that are related to the current situation and especially the things that are important to the Player Characters'. Again assuming equal effort here which I think is fair.
I'm not completely crazy about comparisons to novels, but a great example to me is the Lord of the Rings trilogy compared to the Witcher novels. Tolkien expends a great deal of effort on world building, but not much on developing his characters as fleshed out people. Sapkowski, like Howard before him, is far more interested in developing individual characters. Dandelion, Yennifer, and Geralt feel far more familiar to the reader than Aragorn. Gandalf, and Frodo. You know what they've been through, who they are as people. The relationships they have to various side characters. The overall setting and history while still addressed in the novels does not have nearly the depth of Middle Earth.
It's all about how we focus our energy.