Thanks, the main motivation here is to explore the subject in order to inform and expand understanding of our potential readership rather than me specifically
I just pose as the dumb arse , well it's such a easy roll for me
So think of a fictitious extreme case:
I have a cone made of high density unobtanium that allows me to have a Fs (resonant frequency) of 20 Hz, a cone break-up mode at 5 Khz, all in a 3" driver, with a max excursion of something insane, infinite power handling and thermal capacity, and a sensitivity of a horrible 70 dB at 1 m. As long as I have infinite power, I don't care about its crappy 70 dB sens.
The advent of good class D amps have nudged us a bit closer to infinite power, which makes it possible to pursue even smaller cabinets with smaller drivers (with high excursions) with deeper resonant frequencies.
In fact, I'd go so far as to say that power is so efficient now that the bottleneck is firmly on the driver side.
That wasn't always the case. In the early stereo days, power was so pitiful and inefficient that every driver had to be relatively high sensitivity (and often limited bandwidth), and given the driver tech at the time, big boxes, to get even decent mid-bass.
Many say that high efficiency speakers + low power sounds more dynamic than low efficiency speakers + high power, although it's not obvious why that should be the case. Yes, the lower efficiency speaker may have higher inertia, but F = ma and with enough electromotive force it should be just as 'quick'.