I am not sure I can describe what the "ultra high end" means. I have seen systems not in shows but in brick-and-mortar stores that approach seven figures. I suspect those are sold to very few for undisclosed amounts while those products are halos meant to light the way for buyers to more affordable gear made by the same maker or sold by the same dealer. Other stuff is nearly purely bespoke, custom cabinets, drivers sourced at auction, built by specialized craftsmen who duplicate nearly every step in the manufacture of an original many decades out of production for the very rarefied group of fans/buyers who may travel to other parts of the world just to hear a special setup. There is only so much of a market for those things and the market is expressed by the costly development of new materials and products and the equally costly need for roadshows arranged to draw the interested. Then there is the other high-end market, disparaged by some as appealing to "lifestyle" buyers, which is to say people with money who have expectations that high priced gear be made so it can be compatible with well-furnished living spaces and sound good. Usually that excludes vintage technologies and favors makers that consider good design and engineering that delivers performance without imposing on living space, so B&O, Linn, Dutch&Dutch, Grimm, Kii and others find buyers among whose not-unreasonable needs they meet.
How many people were buying premium Marantz tube preamps in the day, or high-end turntables or Tandberg reel-to-reel decks? Not very many. Most people who might have chosen to buy a better sound system might have bought what my aunts each bought, a KLH Model 20, an all-in-one TT-receiver (AM and FM, germanium transistors--"solid state") and those were seen as not-inexpensive systems for people who liked recorded music. There wasn’t a market for stratospheric gear, it didn’t exist. The ultra high-end as we are referring to is a phenomenon of the past 30 or so years.
Consumers have moved on. Financial pressures in the costs of ordinary things, attractions of portable audio, wireless audio technologies, audio in cars, laptops that can host whole high-definition collections ready to stream to a BT speaker or wireless home system, the disappearance of the recorded "album". Who is meeting these consumers? Smartphone makers, web content distributors like Spotify and Tidal, Amazon and Apple, Chi-Fi developers that deliver inexpensive and decent-quality components that make buying a sound system an attractive and low-risk proposition. Producers of gear at nosebleed prices almost nobody can afford? Not so much.