This is a trend recognized by a few manufacturers who are as a result putting effort into engineering speakers and components that have a smaller footprint and lighter weight while still offering premium sound. Borresen / Aavik, Raidho, and T+A (not the HV Series) are falling into this camp.
With speakers particularly, there’s the ability to use 3D machining to more accurately sculpt the cabinet and design for bracing such that it enables better airflow and less cabinet resonance. As an example, look at the T+A Talis S 300, whose cabinet is machined out of solid aluminum. It has a very narrow footprint and weighs 72lbs, but it goes down to 25Hz and sounds huge. Borresen speakers, similarly can fill huge rooms. I know at Axpona this past year they demonstrated how their monitors could fill a 60x30 space.
Class D amps are advancing this way as well, though I haven’t hopped on that bandwagon yet. I do have the T+A A 200 on my floor, and I found it outperforms the Primaluna Evo 400 amp at 1/3rd of the weight and similar price point.
As it becomes harder to make gear that sounds better, focus will be placed on its form factor and space requirements to make them better integrate into your home/room. So many manufacturers are behind on this, though.