The Atlas shouldn't be infinite, and GGG could learn a few things from Civ 6's map functionality.

First and foremost the biggest QoL feature the Atlas needs is a 2D minimap like Civ 6 has. It makes it much easier to see where you are on the map and quickly navigate to sections of the map.

Although Civ 6's maps are not infinite, they can be fairly large. And anyone who has played Civ knows there are a lot of tools to navigate the map, find units/buildings, etc. And there is a lot more going on in a Civ game. The 3D Alas kind of reminds me of Civ, but its very limited in terms of functionality and makes navigation a headache once you start opening up more of the map.

I think a lot of features like the minimap could still be implemented even with an Infinite Atlas, but I personally don't think it should be infinite. I think it can be very large, but not infinite. I think there should be a way to reset the Atlas and I think there should be more direction on where to explore (mainly to find Citadels). I also think with a non-infinte Atlas it could allow for some sort of "Atlas Prestige" system that upon resetting to a new Atlas gives some sort of bonus or additions. In the long term an Infinite Atlas just sounds like a mess and can get unwieldy very quickly. Regardless, whatever they do there needs to be way more QoL features and starting with the minimap would be my suggestion.

I think it would be better to create a more interactive map, like in Heroes 3. You start with a map of a certain size where you gather resources to build an outpost. This outpost then unlocks the next map and allows you to explore it. This idea could be expanded, for example, by adding the ability to defend your outposts and so on.