Bookstores like to make things easy for themselves by defining categories (a la Seeing Like A State), especially due to the perceived overlap between the readership of the two categories as the weird books the nerdy guys read.

While that may have been true historically, fantasy has a new, blossoming, largely female readership, although you could consider this to be overloading the term 'fantasy' as these new BookTok books seem to have little in common with the old school sword and sorcery.