This is just flat-out wrong.
They may have shot up in popularity after phones stopped having headphone jacks, but there was certainly a Bluetooth headphone market before that.
> Personal media players weren't nearly as mainstream before the iPod.
Again, wayyyyy off base.
Personal CD players were VERY popular and common in the late 90s. I'd wager Napster and the advent of CD burners popularized them even more.
> Almost all of these product markets existed and mostly catered to niche audiences before Apple jumped in.
Cringe. This reeks of the attitude common attitude around 2010 where Apple fanboys would praise Steve Jobs for his innovation when Apple would implement a feature into iPhone that Android had for years.
> If there's one thing Apple excels at, its convincing the mass market to adopt technologies that currently only cater to a niche audience.
They excel at UI/UX. From a purely technical standpoint, they're often a couple years behind, but if you polish the crap out of it, people don't notice.