The allure of two big beautiful towering towers is undeniable, and they would be my preference 100/100, but there are some instances where they can actually be at a disadvantage compared to the bookshelf speaker/subwoofer combo.
In particular, the greatest advantage of the towers, which is the extension downwards, can become the weak point, because in small rooms, or with particularly critical room modes, having two low-frequency fire mouths linked to precise positioning can lead to very unpleasant and difficult to contain results, from this point of view, it can be much easier to position two bookcases and delegate the deep bass to a sub that can be positioned anywhere.
Furthermore, sometimes, to obtain the same musical result, two bookshelf plus a sub cost half of two equivalent towers, and this too is an element to evaluate.
Unfortunately integrating the sub is not a trivial procedure, and the result of a poorly integrated sub is generally disastrous, even more than two towers attached to the wall.