It is not. The original article has a breakdown based on income, which shows similar trends for every income bracket: https://news.gallup.com/poll/284009/library-visits-outpaced-...

But in any case, the conclusion in the title of the article is wrong and not supported by the results.

Looking at the income breakdown at the Gallop link that throwawaylolx posted, it may well be an influence, although conflate seems a bit stronger than I'd put it.

More an effect of income inequality. Plenty of homeless in the high income inequality downtown library, but there's more people visiting in the higher income equality suburbs which swamp that first effect out when averaged nationwide.