I'm a bit tired of seeing "product-market fit" over simplified in posts such as yours. In reality, product market fit isn't black and white. Even when you build something that people want, you might not have product market fit. Even when you've built something that nobody wants right now, you may have still product market fit. And then there are a billion shades in between.

We should talk about nuances of why startups failed. Otherwise, "lack of product market fit" is just jargon for "we failed." Of course, we already know they failed. And since they are startups, they probably didn't fail with millions in revenue.