Shrinking values in a shrinking universe of HiFi (and MidFi) brands.
Even the cornerstone legacy brands are suffering.
I think that a peculiar alchemy of lost creativity (including sucky music), lowering competencies, really cheap electronics prices, declining disposable income of those under 50 and pretty darn good sound out of AirPods, Beats and wireless boom boxes has made the last generation (or 2) of consumers unwilling to matriculate into bespoke gear.
I read somewhere (sorry I can't recall where) that the average age of high end stereo buyers is 57 years old. If true, the guys that buy the stuff we all love here on the AG forum are soon to be unable to hear well, and then dead.
Anecdotally I see HiFi shops that managed to stay open moving to home theater to stay alive as their $10,000 to $20,000 separates sales are not covering the overhead. It appears that only the really large city/ rich areas have Hifi shops now.
Additionally I see used gear on HiFiShark being marked down pretty substantially of the seller needs it gone. Overpriced gear sits on there for months/years.
The same thing is happening to pre 1960 automobiles. The last Goodwood auction was awful for vintage Rollers, MGs, Triumphs, etc. The only cars catching a bid were early 1980s and later Ferraris and other hand-built exotics.
There are exceptions which do not invalidate the generalization. Of course this is just 1 man's observation.