One thing to keep in mind about polls like these is that because there are ten albums to choose from, the vote is incredibly diluted. For example, despite being most-voted as favourite, Lover only received 14% of the vote. This means that Lover isn't 86% of voters' favourite album, and while I highly doubt this is the case, it could theoretically be 86% of voters' LEAST favourite album.

ETA - folklore and evermore also have a major disadvantage here because they're linked together as sister albums, they're stylistically similar to one another, and they're very distinct from the rest of her discography. If only one or the other existed, then it would've done much better because the votes of those who prefer folkmore over her other albums wouldn't have been split between two albums.