At best it can tell you how much air the speaker can move. Audiophiles rely on this spec way too much IMHO, especially when deciding whether or not to add a subwoofer and how to configure one. The room makes liars out of all of the anechoic/quasi-anechoic bass measurements.
IMHO, measuring dynamic compression is of more value for most of us, and the one publication that used to do it (SoundStage) I believe stopped publishing these measurements.
There’s no substitute for listening, and measuring in the room.