Well, boo hoo for the guitar dealers and mass manufacturers – decent guitars (and basses) aren’t an ever evolving product with a limited life - like a family car that is worn out and obsolete after 10 years. You’re selling musical instruments, not refrigerators.
Decent guitars, with a few exceptions, usually play just as well (or better) at 20 or 30 years old than when new. Unless they are physically damaged or subject to extremes of heat or humidity they still play perfectly and any minor electrical or fret problems can be quite easily fixed.
So there is not just an ever decreasing customer base amongst the young, as the article explains, but most older players already have several guitars, and unless they have chronic GAS maybe rather wish they had a few less.
Mass manufacturers can’t keep on churning out millions of guitars a year into an already saturated market, no matter how cheap and well made they are, so maybe their days are numbered.