Yeast is a living organism. They'll do what they want, and not always the same thing twice, even if that's what we would prefer. There are also a lot of variables with different kinds of complex vs. simple sugars in different beer worts, depending on grist, mash parameters, etc., which the yeast have an easier or harder time dealing with from batch to batch. Expect final gravity and thus attenuation to vary between batches and from manufacturer specifications. They can only provide an average or a range, not an exact value.
FYI, Wyeast 3711 and Belle Saison yeasts, as well as other so-called diastaticus yeasts, can ferment up to 96% apparent attenuation for a consistent FG of about 1.002, given the right conditions and enough time for them to finish. Patience is also a factor.
Another FYI, if fermenting cider, wine, or mead, it is very common for a final gravity below 1.000 down to about 0.992-0.994. This is because alcohol is less dense than water, and unlike a malt wort, the simple sugars are easier to ferment to high alcohol levels in these beverages. But again, patience is a factor...
If any fermentation is rushed, the "final" gravity can appear higher than expected if a slow fermentation is still going on. When in doubt, ferment longer to ensure FG has been reached. And then also don't be surprised if it's lower than you expected. The yeasts are alive and they'll do what they want. You can try to control final gravity and attenuation via ingredients and mash parameters, and the biggest choice being selection of the yeast strain..... but they'll still do what they want.