Being able to set the individual cells of the 3D volumetric atmosphere is how you achieve that in the most precise and realistic way possible.
Live weather doesn’t have a single “visibility” value. Live weather receives a complete 3D grid of “virtual atmosphere” from meteoblue surrounding your plane and then blends in data from nearby METARs into that virtual grid. Virtual rays of light travel through that virtual grid of atmosphere, it gets scattered\obstructed by virtual water particles in each cell based on the atmospheric conditions of the cell, and then that’s used to render each pixel of the atmosphere. It can be foggy\cloudy in a single atmosphere cell, it can be foggy in a group of cells, it can be foggy at the base of the mountain and not the peaks, or whatever the case may be. It’s completely dynamic, based on pseudo-real life physics, and is why the lighting effects are so convincing and we can have effects like dynamic rainbows. Everything is completely localized and 3D.That’s how visibility is currently handled. How could you possibly have a single “visibility” setting as part of a preset? With a volumetric atmosphere, you would create these precise conditions by modifying the individual cells of the atmosphere, or some system to automate the process, like being able to modify METAR reports and it automatically does the hard work of filling in the atmosphere cells. That’s what we actually need.