When 'writing' is understood in a more limited context, this article is fine. Clickbait writing is a terrible career, precisely because of the economics the author describes. Yet this says nothing about, say, doing longform journalism --- well, that's at terrible career as well, most likely, but probably for very different reasons than the ones this article plumbs: not because "writing doesn't scale" (the author bemoans not being able to produce more than five or six articles an hour!) but because _creating truth and beauty has always been a renumeratively thankless task._
While there are eras (the heyday of rock n roll for music; the heyday of Condé-Nast-style longform journalism) and people (Leonard Cohen; Ta-Nehisi Coates) that prove there are exceptions to the rule, it remains a truism that unregulated markets, in general, are bad at nurturing minds. This is why universities and musical conservatories were created in the first place. Get thee to a faculty!
It does not surprise me that the author wound up in fintech -- that sounds like a great fit, actually, for someone who explicitly experiences 'writing' (or what the author experiences as writing) as analogous to iron mining. No shade thrown either: that's a valuable mindset! But it's not the one that produces (sparkle emoji) Writing (sparkle emoji).