> Then for some reason they raised over $400M in funding and hired 1,500+ employees

... what the fuck. Certainly explains things

> I still don't know how they're valued at $5B+ when I don't know a single developer who actually uses it anymore

Yep, one of them. I loved Postman but gone back to plain cURL and the dogshit that is IntelliJ's built-in HTTP request tool.

As for the question... easy. Markets can stay irrational for a very long time...