but that actually gets at a more in-depth answer, which is that i think a reason generated output can feel meaningless is if it lacks meaning, an expressive reason to be. or it might indicate that the presentation isn't supporting it enough. it's really an art or design answer rather than technical.
i think it's a lot like the problem of drawing repeating patterns. yes, a lot of patterns can repeat. but can you make a repeating pattern which draws the attention to relevant details, which has sub-structures which are worthy of attention within each iteration, which is relating to repetition well
i think there's multiple parts to it the novelty of a generative game world won't feel greater than it will in a directly authored one for the amount of work that went in. in fact generators are a lot of extra work to get right, and combinatoric possibilities aren't novel to the end player
i think what you gain though is vast freedoms in latitude for player expression within that space, a robustness and spatial breadth that allows them (or natural events in the world itself) to destroy or remake that space when engaging with it with action principles they wouldn't otherwise have