The game has periodic expeditions that have some story to them, and there is the main overarching story plus the “Journey to the Center” bit
But yea, it’s mostly a sandbox where you make cool bases (and now cool space ships) or try to make number go up and grow an intergalactic trading empire.
Yes. The addiction isn’t usually the problem itself but rather an unhealthy coping mechanism for some deeper issue that the body/mind is trying to get relief from.
It can become an issue itself, as “addiction”, by definition, is a chemical dependency on an outside substance that ends up replacing natural bodily functions, which is why true addictions come with withdrawal symptoms.