On the face of it that argument is a bit specious, IMO: it's like saying you have no freedom as an individual because the parameters of your life have been set by the laws of physics. And sure, there are philosophers who
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, but if you are going to accept that free will exists at all, then the fact that you are evolving within a set of rules doesn't negate it.
Note that I specifically excluded from my example the quests-on-rails that many of those games add on top of their world systems. In Skyrim, you can totally live the life of a normal Iron Age person, doing a job, hunting and making tools for a living, with many different outcomes and playstyles, without touching a single quest. There is even a "no hero" mod that makes this the whole experience... The argument is even more flagrant in Stellaris or Endless Space, where the base game comes with nary a quest (or event chains, as they call them), and you only get those from DLCs.
Likewise in SJ-X, you could totally ignore the quests (or perhaps only do those that grant access to new locations), and just live the life of a greedy trader only in for the credits, or a pirate in only for the loot. Which would be respectively two other actual games that are available on Steam, and probably fun in their own right, if maybe a bit thin.