I don't really want to rag on someone who's clearly more successful and experienced than me but I read this article and I don't know what it's trying to say beyond, "know your customer."
Another quote from him, "you don't know a market until you're in it."
It's impossible to tell what product market fit is unless you're actually out there trying to fit something into it a real market. Like with the Lyft example (as presented) screams to me like pure luck. How did they know the market valued those things? How did they evaluate which elements had the best ROI to get right, and how to prioritize?
I just feel like this article is shockingly light on insight. But then again, we often need someone to smack us with common sense. On the other hand, most smart people know when they're pounding a square peg into a misshapen hole. The hard part is knowing what shape the hole is or if it even exists, and that's the kind of content I wish this article had more of.
Tangent: is there a market for a book full of business-isms and one liners? I've been pushing my dad to write one for years...