At its most optimistic lense, we're talking digital adoption/ratio of 60%.
With that significant a retail drop, it's performing poorly enough that digital will not offset unit sales, even if they're more profitable due to digital.
Furthermore, to a certain extent, even sequels that do "on par" with the first game could be seen as under-performing. If a game is made with the hope of expanding the brand so that the franchise becomes bigger and more popular, Battlefront 2 has surely not expanded the audience. At best it retained 80-90% of the first game's player base.