If you're just _hacking_ a few simple calls, curl is the way to go.
But if you're working in a team, with multiple environments, with complex payloads, authentication, doing dozens of API calls everyday...
Having a software able to manage libraries of endpoints, parameters, simple environment switching, included auth, sharing between team members... is a big time saver.
I personally prefer IntelliJ's HTTP Client[0] since I always have my IDE open, the files are not obfuscated in a gibberish format and can be versioned/shared through Git.
But when I start working on an existing project, having a Postman collection to rely on is a huge time-saver, instead of having to go down in-existent API docs or trying to infer from the code itself.
This and also when you newly join a team it is more productive to start using the tooling what they are using and move to preferred tooling once familiar with the API endpoints.
If you're just _hacking_ a few simple calls, curl is the way to go.
But if you're working in a team, with multiple environments, with complex payloads, authentication, doing dozens of API calls everyday... Having a software able to manage libraries of endpoints, parameters, simple environment switching, included auth, sharing between team members... is a big time saver.
I personally prefer IntelliJ's HTTP Client[0] since I always have my IDE open, the files are not obfuscated in a gibberish format and can be versioned/shared through Git. But when I start working on an existing project, having a Postman collection to rely on is a huge time-saver, instead of having to go down in-existent API docs or trying to infer from the code itself.
[0]: https://www.jetbrains.com/help/idea/http-client-in-product-c...