Some but not all of what the author says is true. PMF is a continuum, but also a threshold phenomenon below which it is better called wishful thinking. PMF is dynamic and can be lost, but that is more a question of the M in which it occurs, and the competitive forces there. PMF and defensibility are two quite different things.
PMF is the sine qua non of startups. You should obsess over getting there. Once you have it, you hold a ticket to the arena. Then you have to fight to survive.
The idea of PMF is explored much more helpfully here:
Experimentation in these contexts is difficult to make good inferences from. I'd like to have read more about how experiments are designed to work well with uncontrolled environments, how to make inference for short-term prediction, and how to plan multiple small experiments to usefully exhaust a search space.
Still, thank you for writing. I enjoyed it. I'd love recommendations for more procedural knowledge if you have any.
PMF is the sine qua non of startups. You should obsess over getting there. Once you have it, you hold a ticket to the arena. Then you have to fight to survive.
The idea of PMF is explored much more helpfully here:
https://pmf.firstround.com/
I wrote about it here:
https://vonnik.substack.com/p/how-to-be-lost