A lot depends on the founders. There's plenty VC funded, OSS-originated businesses that don't suck. GitLab comes to mind. There's no reason to immediately assume httpie is going to be the Postman story repeated, although I agree that with VC funding it's more likely than without.

https://httpie.io/about says they've had a seed round already. Looked it up because that sounds… well it is what it is.