The ears usually wear out before the speakers do. Given some sonic degradation over time, it is likely so gradual to even be noticed, if at all, or subject to the “used to it” effect. Playing or swapping out will produce sonic differences. Is the result an actual improvement? Only your hairdresser knows for sure. Exhibit A, most of this forum is dedicated to sonic perceptions 🙃
How long does it take a decent quality speaker to "wear out"?
After all, they do have moving parts and capacitors. . . .
(I suppose that "decent quality" s a relative term. FTR, I am running a pair of the older B&W 805s, and for all I know, they may not actually meet the criteria of "decent quality.")