Interesting that in the title, stated in absolute terms in the text, and from the designers they interviewed, they cite getting lost as crucial for the genre. Personally, I disagree. Getting lost has tended to be why I didn’t care for certain games in this genre, like Axiom Verge, and it soured my otherwise higher opinion of games like Hollow Knight and Symphony of the Night. Still, I think this is a good exploration of the genre and what makes it tick.
I suppose I should’ve been clearer there, I really just meant the Koji Igarashi-era games, not Classicvania. As the other comment mentions, the term Metroidvania was actually originally coined to separate the two eras of Castlevania, before the genre exploded in popularity and it became repurposed.