My personal experience with the evolution of loudspeakers don’t extend for longer than back to the late 70’s, and though this mayn’t warrant calling these earlier encounters vintage speakers per se, there’s definitely been a tendency of speakers being progressively smaller (and then perhaps bigger again). As an example back in the late 80’s a pair of JBL 250Ti’s could be had for roughly $3,500 (following a decline in the exchange rate of the Dollar), and though you could arguably have a different, more "hifi-ish" sound for that amount of money (or even less), what you got was a big, versatile, high quality visceral sound, and two lovely pieces of furniture to boot. The JBL 250TI Jubilee’s could be had for about a $1,000 more a pair a little over a decade later, a fine value as well (as I see it).
I like seeing JBL go back to the use of compression drivers in tandem with bigger 15" bass/mid drives for the last decade or so with their "commercial" and monitor series (except of course the Everest’s/K2, which have been more or less less true to their heritage line), but the price for these, even where no real veneer was used, was/is steep, and a reflection of something other than inflation alone; the market sees a progressive use of smaller speakers that are refined into being quite expensive, and their bigger iterations are of course priced accordingly (i.e.: very expensive). Big, visceral sound is a quality in itself, I find, and a very important parameter in making you give-in to the music as something other than reproduced. It’s a shame then that where this is to be attained the price may be out of reach or requiring extra monetary priorities, if the desired size of the speakers is even to be had.
The main problem, to my ears, is the almost exclusive reliance on the direct radiating principle, as this generally shortchanges size (i.e.: radiation area) and not least sensitivity (the latter of which excludes the use of smaller-watts amps). I’ve no doubt that speaker technology has advanced significantly over the years, but its application into actual designs is hampered by before mentioned.
Perhaps an analogy to imagery is in place: seeing 2K or 4K films (or most any viable resolution, for that matter) on screens below 50-60" seems not to immerge you in the visuals as effectively as could. It is said that for the eyes and mind to properly exclude visual information not created by the screen itself, a particular minimum ratio of the distance to the screen in relation to its size is required (which generally equates to some +80-90" for home use). This way your eyes (and mind) can relax more effectively in the imagery, and hereby exclude the surrounding "noise" that is the environment of the room. Not only that; the effective resolution, certainly with 2K and not least 4K, cannot be taken advantage of unless the screen extends or certain size (again, in relation to the distance to the screen).
In a sense this extends to speakers as well: smaller speakers, highly refined and resolving, can’t seem to "unfold" the proper image in all its glory, but remains instead a minimized presentation of an event, and hereby too obviously reproduced. To me, one major parameter in sound reproduction is size, and I’d rather have that poorly resolved than a smaller ditto highly resolved. Combine the two, size and resolution, and we’re talking.
Added to that is the by-product of high sensitivity, which is not so much about max SPL per se (more like headroom), but the difficult-to-articulated sense of ease. It usually also incorporates the quality of low level resolution, which is an added (and very important) bonus to the ability to play insanely loud (not that that’s needed, but it’s an integral part of named "ease" and versatility).
Modern speakers are no doubt more refined, resolved, airy, and in a sense less colored, but it comes at the expense of a generally minimized presentation, and one that also plays too thinly or even malnourished (both of which could be called coloration as well, by virtue of absence). If the advance in technology were to be applicated with older designs of bigger size and higher sensitivity, I’d feel we could be talking about overall advancement. Thankfully there’s a wide range of speakers to choose among, and so the advancement may be had "locally."