Frequency response + or - 1 dB ??


The technical material world is full of incredible precision - watches as a mundane example. Why can’t the best loudspeaker manufacturers create a loudspeaker with + or -  1/2 dB frequency response within the rather limited 20 to say 30,000 cps range? 
ptss
What would be the point? Every room has a different frequency response. 
The actual recorded frequency response of any given speaker may actually be higher than +/- 1 dB.  In all honesty, a 1-2 dB variance is really nothing at all when you are looking at radically different speakers.  A single driver could have up to a 2-3 dB variance through a specific frequency range.