The reason why you might want to care is enlightened self-interest. If there are fewer thirtysomethings buying decent audio as part of the 'settling down' process (good audio might have been an aspiration for the young of past generations, but the typical first-time buyer of good audio equipment was commonly in their mid 30s), companies that supply them will ultimately shrink in size and number. Even if there are a lot of people buying these products, just not in your part of the world, the same thing happens because the support network needed to supply those products locally becomes increasingly untenable at its present scale. That only leaves the 'carriage trade' luxury goods, supplying very high-end products to those who are mature enough to appreciate the finer things in life and don't mind paying for them.
Put simply, fewer aspiring audiophiles today means fewer audiophiles tomorrow means fewer audiophile companies the day after tomorrow. And, because the newly-minted audiophile tends to buy more entry-level equipment more regularly than the fully-grown audiophile, that means higher value, higher priced products sold to those still interested. So, when you go out to buy that new or replacement product in a few years time, you find it harder to buy something in your price range and find the selection of products on offer greatly constricted.
Part of the reason why there seems to be a disproportionate slant toward increasingly expensive products in audio today is because we are already about 15 years into the 'fewer aspiring audiophiles' part. Millennials/Generation Y/Echo Boomer kids largely didn't buy into the idea of good audio, because they had games consoles to take their place, and the uptake now that they are in their 30s is disappointingly low in the West. The iGen that follows them have even less interest in home audio because they consider music to be something you carry around with you. Interestingly, iGen kids are even starting to look upon consoles as a throwback to a bygone age where you had to sit in one place to play games, and I'd guess those who come next (Generation Alpha? the Cloud Generation?) will view the idea of locking your digital self to bits of hardware - and using different devices for different tasks - as 'charmingly quaint', or whatever the 2020 version of the word 'lame' proves to be.