One aspect of having subs that is not often mentioned, is that there is a lot of ambient information carried in the lowest frequencies. This adds to the sense of scale and space. Low frequencies travel long distances and pass through barriers, providing information about distant musical events or the overall acoustic size of a space.
Now, mind you, this is most noticeable with classical music, where all the musicians were playing at the same time, in the same acoustic space, where the recording engineer endeavors to capture the natural soundstage and ambience of the acoustic space, and the musician’s position within it.
Even floor standing speakers will benifit.

