I too like this approach, because the format is simple and text-based and you can maintain it in your git repository.

My main gripe with Postman and Insomnia isn't actually the web based UI, but the lock-in. You can't access the files that they store their data in easily. Postman especially tries to push people towards getting their per-seat 'cloud' subscription if you want to share sets of HTTP requests.

But using this text-based REST client, you don't have this file lock-in.

For IntelliJ this feature is actually built in, I believe it uses the same syntax.